This allows for a 2 stage trigger setup on a barricade or stockade, to replace the rev switch.
It makes use of a stock switch, which is glued into the in the blaster as circled in red then printed part and wired up with the 'normally closed' so that when the switch is released it completes the circuit.
The printer part then needs screwing onto the under side of the trigger and positioned so that when the trigger is fully forward it pushed the switch.
The the blaster can be rewired in the normal way
i did however keep the rev side switch so the blaster can be turned off, this makes it easier when barrel rotation is needed for reloading