DESIGN CARTRIDGE: .223/NATO 5.56 – LENGTH: 6.1 – LENGTH ADDED: 5.5 – DIAMETER: 1.5 – WEIGHT: 21 oz. – MATERIALS: STAINLESS STEEL – FINISH: SALT BATH NITRIDE – NSR: 32-34 DB – The most popular Black Rain Ordnance Inc. Silencer for military applications (including FULL-AUTO) and varmint hunters the BRO-ARIS provides the maximum noise reduction in a 6 can. This silencer produces excellent noise flash and recoil suppression. Like all of the B.R.O. Silencers it is designed for HEAVY USE and comes with a disassembly tool and unique epsilon baffles for easy removal.