Patented CAM-LOK (Covert Application Mount - Locking) universal QD piston attachment system; 3 mounting positions, 120 degrees separated for rapid mounting; Internal taper surface locks in place with interfacing barrel adapters and drastically reduces or eliminates common baffle/end cap strikes; Compatible with Universal QD pistons barrel adapters (sold separately); Total system weight is identical to legacy direct thread pistons; H900 heat treated for improved durability and wear resistance; 17-4 stainless steel material