This is the Adams Arms Retro-Fit Piston Driven Cycling System for the AR-15/M-16 rifle. Adams Arms' piston driven systems replace the impingement system currently used in the mil-spec AR-15, M-16 type rifles, offering the following benefits and features:
Lowers recoil 30 to 40 percent by using a short stroke shaft
Improves accuracy by lowering recoil
Faster target acquisition
Eliminates hot gases from entering the receiver
Makes the firearm more reliable over a longer term of use
Easy access from front of block with out removing hand guard
Includes one-piece bolt carrier, handguards and handguard cap