This is a std Pico relay switch from Dimension Eng but has been modified to use as a engine cutout for Petrol powered cars by Outlaw RC.

By fitting this unit to your 3 channel radio system you can cut engine from your radio unit, it will also cut engine out if your batteries fail or disconnect.

This is the best used with a std failsafe unit you can get for your petrol car or built-in radio failsafe!