Airsoftjunkiez just had a huge restock of HPA triggers from SPEED Airsoft. These are the tunable M4 flat triggers  designed to work with Polarstar and Wolervine HPA conversion systems.

The SPEED HPA triggers incorporaye dual adjustment set screws which will enable a trigger pull under 1mm with ease. The triggers will also include a specially designed coil compression spring that reduces the pull tension, so players with the Polarstar and Wolverine systems can rip off lightning fast strings easily even in semi-automatic mode.