The new SPEED Airsoft HPA/MOSFET M4 triggers released are designed to work with Polarstar HPA conversion systems. The SPEED HPA/MOSFET M4 triggers incorporates dual adjustment set screws which will enable a trigger pull under 1mm with ease. The SPEED HPA/MOSFET M4 triggers also includes a specially designed coil compression spring that reduces the pull tension, so players with the Polarstar systems can rip off lightning fast strings easily even in semi-automatic mode.