The Binary Firing System GEN 3 (BFSIII) is a 3-position trigger. In position 3 it fires one round on pull and one round on release. This trigger is ideal for having more fun than you thought was possible with your Ruger PC Charger and Ruger PC Carbine. - TRIGGER OPERATION: - Position 1 Safe -Will not fire - Position 2 Semi -Fires 1 round per pull - Position 3 Binary -Fires 1 round on pull and 1 round on release - FEATURES: - Release round can be canceled by simply moving our Patent Pending selector out of Binary mode while holding the trigger back - Works in most 9mm and .40 Cal Ruger PC Carbine trigger housings - Great for competition shooters tactical shooters and recreational enthusiasts - Gunsmith Installation Recommended