Features 1 Mounting orientation, for simple mounting in approximately 4-5 seconds 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 QPQ Nitride finish for attractive, durable black finish