L'antre Du Dingo checks out another HPA engine for airsoft use. The Genesis HPA Engine For Version 3 Gearbox is single-solenoid and settings are changed via bluetooth. It is a closed boltt type that allows one to fire in auto and semi-auto mode with input pressure range at 80-140PSI. As for battery it can work from 7.4 or 11.1 Volts and you can adjust the rate of fire 400-2000 rpm and cut-off mode from 1 to 3 shots. Other features are tracer hop-up or fire simulator control mode and sleep mode with zero power consumption.