Accessories & addons
We have plenty of add ons and accessories to expand your products or complete your rocket setup. From external temperature sensors to servo control boards and even launch pad blast deflectors.
Magnetic smart switch
RRP: £22.52 $29.86 €26.06
GTIN: 5061078870037
MPN: MRS_MAG1
Our magnetic switch is a step up from your average mag switch.
The sensitive magnet sensor actions a state change after you hold a magnet near it for 2 seconds.
If you turn the device on, it will give 5 short beeps to let you know it's on, and turn on the onboard LED.
When the device turns off a long single tone will sound.
While turned on the buzzer will give a short beep every 10 seconds so you can listen to your rocket and know your switch is on.
The magnetic switch saves it's state in non volatile memory so any short power outages will not reset the switch and power will remain ON or OFF once restored.
We've also included two decently sized capacitors that can power the onboard microcontroller for 10 seconds to avoid it shutting down at all during short power loss events.
Furthermore, there is a onboard button that you can use to action the switches state change instead of a magnet. There is also a input connection point that you can use with a 3 to 22 volt input signal to action the switch (a 3.3V output point is available to connect a external push button to this point). You can also program the switch yourself if you wish to use it in a different way. The final pin is a UPDI programming connection, you can program using Arduino and the Adafruit UPDI HV Friend board if you fancy a project!
Small, light and versatile
- Up to 35A peak current for 0.5s and 20A for 2-3 seconds.
- 10A continuous current.
- Small size 20 x 15mm (~0.78" x 0.59")
- Just 1.1 grams weight (~ 0.035 oz)
- Input range of 2.9V to 12V
- OFF mode current of just 4.5uA (About 3.2mah per month!)
- Onboard microcontroller, buzzer for audible indication of state, and state LED
- Programmable for custom operation if you require.
- Reverse polarity protection.
- 2oz, 4 layer high quality PCB and full surface mount components.
- State memory. The switch will always return to it's last state after power loss.
- 4x 2.7mm mounting / terminal holes / solder with additional smaller solder holes for maximum installation options.
The sensitive magnet sensor actions a state change after you hold a magnet near it for 2 seconds.
If you turn the device on, it will give 5 short beeps to let you know it's on, and turn on the onboard LED.
When the device turns off a long single tone will sound.
While turned on the buzzer will give a short beep every 10 seconds so you can listen to your rocket and know your switch is on.
The magnetic switch saves it's state in non volatile memory so any short power outages will not reset the switch and power will remain ON or OFF once restored.
We've also included two decently sized capacitors that can power the onboard microcontroller for 10 seconds to avoid it shutting down at all during short power loss events.
Furthermore, there is a onboard button that you can use to action the switches state change instead of a magnet. There is also a input connection point that you can use with a 3 to 22 volt input signal to action the switch (a 3.3V output point is available to connect a external push button to this point). You can also program the switch yourself if you wish to use it in a different way. The final pin is a UPDI programming connection, you can program using Arduino and the Adafruit UPDI HV Friend board if you fancy a project!
Small, light and versatile
- Up to 35A peak current for 0.5s and 20A for 2-3 seconds.
- 10A continuous current.
- Small size 20 x 15mm (~0.78" x 0.59")
- Just 1.1 grams weight (~ 0.035 oz)
- Input range of 2.9V to 12V
- OFF mode current of just 4.5uA (About 3.2mah per month!)
- Onboard microcontroller, buzzer for audible indication of state, and state LED
- Programmable for custom operation if you require.
- Reverse polarity protection.
- 2oz, 4 layer high quality PCB and full surface mount components.
- State memory. The switch will always return to it's last state after power loss.
- 4x 2.7mm mounting / terminal holes / solder with additional smaller solder holes for maximum installation options.
Where to buy
Output Roc 2 - high current I2C expansion board
RRP: £37.99 $50.37 €43.96
GTIN: 5061078870136
MPN: MRS-OUTROC2
COMING SOON! The first batch is due with us on the 10th March 2026
The Output Roc 2 is a small I2C expansion board that adds two high current outputs to your Mercury V1 altimeter (or other altimeters of ours with I2C ports).
You can of course use it for your own projects too!
It uses the same output controller IC's that the Neptune and Jupiter use which offer extremly low resistance. They are protected against over heating and over current with auto-restart.
The board has a handy XT30 connector for your external battery, and comes with two push fit connector boards and two 30CM connector cables.
The board uses Molex NanoFit connectors which means you do not need to do any soldering to use these outputs. These cables have secure connections and won't come out accidently.
Rated for 8 amps continuous without overheating on each of the two channels.
Capable of peak current of 20-30 amps for a short period per channel.
There are solder holes for the outputs too should you choose, and 4 more connection holes which allow you to view the current on each channel (Analog output once selected 0-3.3V range) if you are using this board for your own project.
Longer Molex Nano Fit cables are available if required, as well as connection boards with screw terminals, solder pads or push fit connectors (included).
The Output Roc 2 is a small I2C expansion board that adds two high current outputs to your Mercury V1 altimeter (or other altimeters of ours with I2C ports).
You can of course use it for your own projects too!
It uses the same output controller IC's that the Neptune and Jupiter use which offer extremly low resistance. They are protected against over heating and over current with auto-restart.
The board has a handy XT30 connector for your external battery, and comes with two push fit connector boards and two 30CM connector cables.
The board uses Molex NanoFit connectors which means you do not need to do any soldering to use these outputs. These cables have secure connections and won't come out accidently.
Rated for 8 amps continuous without overheating on each of the two channels.
Capable of peak current of 20-30 amps for a short period per channel.
There are solder holes for the outputs too should you choose, and 4 more connection holes which allow you to view the current on each channel (Analog output once selected 0-3.3V range) if you are using this board for your own project.
Longer Molex Nano Fit cables are available if required, as well as connection boards with screw terminals, solder pads or push fit connectors (included).
ServoRoc4 a 4 port servo expansion board for the Mercury V1
RRP: £37.99 $50.37 €43.96
GTIN: 5061078870099
MPN: MRS-SERVOR4
COMING SOON! ETA: 20th February 2026
The ServoRoc4 offers two traditional style servo connectors and two smaller 1.0mm pitch micro connectors as well.
It takes a XT30 connection battery of 1S to 4S and connects to your Mercury V1 via the I2C expansion port.
This makes using servos in your rocket extremly easy. You can then use servos via the onboard rules system or special systems such as the Air brake mode as well.
Of course you can use this board with your own projects as there are plenty of drivers for this chipset as well.
We've included a super accurate CMOS crystal to offer ultra accurate signal generation for the servos.
The ServoRoc4 offers two traditional style servo connectors and two smaller 1.0mm pitch micro connectors as well.
It takes a XT30 connection battery of 1S to 4S and connects to your Mercury V1 via the I2C expansion port.
This makes using servos in your rocket extremly easy. You can then use servos via the onboard rules system or special systems such as the Air brake mode as well.
Of course you can use this board with your own projects as there are plenty of drivers for this chipset as well.
We've included a super accurate CMOS crystal to offer ultra accurate signal generation for the servos.
Snapshot screen for Mercury V1 altimeter to view flight summaries
RRP: £37.32 $49.48 €43.18
GTIN: 5061078870075
MPN: MRS-SNAPSHOT
The Snapshot screen for the Mercury V1 altimeter.
This screen shows you a brief summary of your most recent flight, as well as some device data.
You can also get summaries from the Mercury via USB serial or logging into the Mercury's WiFi as well as full data on the Altimeter Cloud.
This screen is extremely handy for an easy method to view the data, and it's great when you need to retrieve summary data from many altimeters such as at competition. This is based on the Waveshare 1.85C development board and screen, so if you already own one you can just install our firmware from the firmware update page on your own as well.
In order to use the screen you just plug it into your Mercury's I2C expansion port (with the Mercury off).
When you turn your Mercury on it will enter display mode and show the data on the screen.
The screen also doubles up as a ESP32-S3 development board should you want to use it for your own projects as well.
You can always put the original firmware back on with ease from our firmware update page.
The screen is a round 1.85" touchscreen.
Included
1x Snapshot screen
1x StemmaQT type I2C cable
For the best and most stable results, you should power the screen with a USB-C cable, either from a power bank or your smart phone.
If your Mercury has more than 50% battery, then it can power the screen, but this is not the recommended method as it will deplete your Mercury's battery quite quickly.
The screen also comes in a version with a battery included so you can choose this one if you want the most reliability all day without worry.
This screen shows you a brief summary of your most recent flight, as well as some device data.
You can also get summaries from the Mercury via USB serial or logging into the Mercury's WiFi as well as full data on the Altimeter Cloud.
This screen is extremely handy for an easy method to view the data, and it's great when you need to retrieve summary data from many altimeters such as at competition. This is based on the Waveshare 1.85C development board and screen, so if you already own one you can just install our firmware from the firmware update page on your own as well.
In order to use the screen you just plug it into your Mercury's I2C expansion port (with the Mercury off).
When you turn your Mercury on it will enter display mode and show the data on the screen.
The screen also doubles up as a ESP32-S3 development board should you want to use it for your own projects as well.
You can always put the original firmware back on with ease from our firmware update page.
The screen is a round 1.85" touchscreen.
Included
1x Snapshot screen
1x StemmaQT type I2C cable
For the best and most stable results, you should power the screen with a USB-C cable, either from a power bank or your smart phone.
If your Mercury has more than 50% battery, then it can power the screen, but this is not the recommended method as it will deplete your Mercury's battery quite quickly.
The screen also comes in a version with a battery included so you can choose this one if you want the most reliability all day without worry.
I2C expansion hub (4 ports)
RRP: £5.99 $7.94 €6.93
GTIN: 5061078870129
MPN: MRS-I2CHUB
COMING SOON: ETA is 7th March 2026 for the first batch.
The 4-port tiny I2C expansion hub lets you connect one I2C port to 3 extension boards.
You can use it to add the two extra high current outputs, the Servo board and a MT1 temperature sensor to your Mercury V1 for example.
The board has TVS diodes to protect against static and a small green LED that indicates when it sees power.
This Hub can work with 3.3V and 5V I2C.
Two 3mm screw holes, one at each end allow you to mount this securely in your electronics bay.
The 4-port tiny I2C expansion hub lets you connect one I2C port to 3 extension boards.
You can use it to add the two extra high current outputs, the Servo board and a MT1 temperature sensor to your Mercury V1 for example.
The board has TVS diodes to protect against static and a small green LED that indicates when it sees power.
This Hub can work with 3.3V and 5V I2C.
Two 3mm screw holes, one at each end allow you to mount this securely in your electronics bay.
Molex Nano-Fit 8A cable assemblies (30cm / 100cm / 200cm)
RRP: £3.99 $5.29 €4.61
GTIN: 5061078870143
MPN: MRS-MOLEX30
Molex Nano-Fit cables work solder free and completly securely with our Neptune and Jupiter flight computers (ETA September 2026) as well as our Output Roc 2 expansion board for the Mercury altimeter.
These cables are stocked in 30cm, 100cm and 200cm lengths pre-assembled and offer 8 Amps continuous current. Which is plenty for pretty much anything in a model rocket.
You can connect these cables to our connection boards where you need them offering a plug and play system without any soldering requirements.
These cables are stocked in 30cm, 100cm and 200cm lengths pre-assembled and offer 8 Amps continuous current. Which is plenty for pretty much anything in a model rocket.
You can connect these cables to our connection boards where you need them offering a plug and play system without any soldering requirements.
MT1 tiny temperature sensor (I2C)
RRP: £15.99 $21.2 €18.5
GTIN: 5061078870082
MPN: MRS-MT1
Our MT1 temperature sensor can be used with our Mercury V1 altimeter.
It allows you to install it with a hole through your rocket's body tube to log accurate atmospheric temperature.
You can use this sensor for your own projects to as it uses the TMP117AIYBGR sensor. There are lots of libraries available for this sensor type.
You can adjust the I2C address with the onboard solder pad if you need to run two sensors on one I2C.
The MT1 sensor is accurate to +/- 0.1C between -20C and +50C.
It can also achieve +/- 0.15C between -40C and +70C.
The IC sensor uses just 3.5uA at 1Hz sensor reads.
The PCB is 14mm x 6.5mm in size with a STEMMA-QT type I2C connector on the back.
The sensor chip on the PCB measures around 1.5mm x 0.98mm.
The sensor board weighs in at just 0.19g.
Supply voltage range is 1.7V to 5.5V. If using it with our Mercury altimeter this will supply the sensor with 3.3V
Supplied with a short I2C cable compatible with the Mercury altimeter.
It allows you to install it with a hole through your rocket's body tube to log accurate atmospheric temperature.
You can use this sensor for your own projects to as it uses the TMP117AIYBGR sensor. There are lots of libraries available for this sensor type.
You can adjust the I2C address with the onboard solder pad if you need to run two sensors on one I2C.
The MT1 sensor is accurate to +/- 0.1C between -20C and +50C.
It can also achieve +/- 0.15C between -40C and +70C.
The IC sensor uses just 3.5uA at 1Hz sensor reads.
The PCB is 14mm x 6.5mm in size with a STEMMA-QT type I2C connector on the back.
The sensor chip on the PCB measures around 1.5mm x 0.98mm.
The sensor board weighs in at just 0.19g.
Supply voltage range is 1.7V to 5.5V. If using it with our Mercury altimeter this will supply the sensor with 3.3V
Supplied with a short I2C cable compatible with the Mercury altimeter.
Manual / Full specifications
3 pack screw switches
RRP: £6.49 $8.6 €7.51
GTIN: 5061078870013
MPN: MRS-SS1
Our screw switch is a reliable and secure way of turning your electronic systems on or off in your rocket. You can also use them as further isolating switches should you choose as well such as to be able to turn on your electronics while keeping your igniters isolated for safety.
Produced from a 1.6mm thick PCB with 1oz copper traces 1.3mm in width to the screw terminal.
This switch is capable of 5 amps continuously safely and considerably higher short term bursts. We suggest using this switch for up to 18 volts AC or DC maximum.
It has two M3 mounting holes making it easy to secure your switch where you require.
Supplied in a bag with 3 switches.
As this switch is turned on or off using just a screw driver you only need a small hole to access the switch from outside your rocket.
Produced from a 1.6mm thick PCB with 1oz copper traces 1.3mm in width to the screw terminal.
This switch is capable of 5 amps continuously safely and considerably higher short term bursts. We suggest using this switch for up to 18 volts AC or DC maximum.
It has two M3 mounting holes making it easy to secure your switch where you require.
Supplied in a bag with 3 switches.
As this switch is turned on or off using just a screw driver you only need a small hole to access the switch from outside your rocket.
Rail mount blast deflector plate 4mm stainless steel 300 x 250mm (~11.8" x 10")
RRP: £47.40 $62.85 €54.85
GTIN: 5061078870105
MPN: MRS_RAIL_BLAST_300250
Heavy duty blast deflector plate for rail model rocket launch pads.
Note: This is only the blast deflector plate along with two rail nuts & bolts for 6mm slot rail, the stand and rail is available seperately or as a bundle.
This blast deflector will last as it's cut from solid 4mm thick stainless steel sheet and weighs in at 2.5Kg
It has two holes for M6 bolts to mount to your pad and comes with the rail nuts and bolts for standard 6mm rail slots.
Suitable for 1010 Rail, 20mm rail, 30mm rail and all sorts of other sizes too.
It's bent to around 45 degrees, you can adjust this by mounting it to your rail and bending it by hand, but please note the joint will crack if you keep changing the angle.
We advise only ever making a single adjustment and do not exceed 90 degrees.
Note: This is only the blast deflector plate along with two rail nuts & bolts for 6mm slot rail, the stand and rail is available seperately or as a bundle.
This blast deflector will last as it's cut from solid 4mm thick stainless steel sheet and weighs in at 2.5Kg
It has two holes for M6 bolts to mount to your pad and comes with the rail nuts and bolts for standard 6mm rail slots.
Suitable for 1010 Rail, 20mm rail, 30mm rail and all sorts of other sizes too.
It's bent to around 45 degrees, you can adjust this by mounting it to your rail and bending it by hand, but please note the joint will crack if you keep changing the angle.
We advise only ever making a single adjustment and do not exceed 90 degrees.
Rail mount adapter plate for Triton multi stand (MSA200)
RRP: £36.00 $47.73 €41.66
GTIN: 5061078870112
MPN: MRS_RAIL_ADAPTERMSA200
Rail mount adapter plate.
This product allows you to bolt a launch rail directly to a Triton MSA200 multi stand.
Produced from thick 5mm thick solid stainless steel. This adapter includes two spacers, the adapter plate bolts and washers to swap the Tritons default holder to a rail mount system.
Note: This is only the blast deflector plate along with two rail nuts & bolts for 6mm slot rail, the stand and rail is available seperately or as a bundle.
Suitable for 1010 Rail, 20mm rail, 30mm rail and all sorts of other sizes too.
We also sell a heavy duty rail blast plate, launch rail and rail mount bubble levels to complete your pad.
Or grab a bundle of everything and make a saving!
This product allows you to bolt a launch rail directly to a Triton MSA200 multi stand.
Produced from thick 5mm thick solid stainless steel. This adapter includes two spacers, the adapter plate bolts and washers to swap the Tritons default holder to a rail mount system.
Note: This is only the blast deflector plate along with two rail nuts & bolts for 6mm slot rail, the stand and rail is available seperately or as a bundle.
Suitable for 1010 Rail, 20mm rail, 30mm rail and all sorts of other sizes too.
We also sell a heavy duty rail blast plate, launch rail and rail mount bubble levels to complete your pad.
Or grab a bundle of everything and make a saving!