An extremely rugged suppressor the HX-QD 556 is built with proven Flow-Through technology delivers hearing safe mid-130s dB performance has no barrel length restrictions is full-auto rated and easily passes the USSOCOM Reliability Stress Test � it�s the ideal suppressor for all 5.56 rifles. - Materials & Finish: Unlike traditional suppressors that manage trapped gas intense heat and pressure with blast baffles OSS�s Flow-Through technology redirects expanding gases forward allowing us to use 17-4 stainless steel deflectors and internal Grade 5 Titanium coils. The result is a remarkably cooler and extremely durable suppressor. The HX-QD 556 has a fully-welded outer body made of 17-4 heat treated stainless steel coated with C-series high temperature black Cerakote. - Sound Pressure Levels: The HX-QD 556 is the optimal choice for the widest range of 5.56 caliber rifles. Sound pressure levels are measured at the shooters ear to comply with current military specifications: - 130 � 134 dB on 20� AR15 DI using commercial grade 55 gr ammo - 133 � 137 dB on 16� AR15 DI using commercial grade 55 gr ammo - 138 � 142 dB on 10.5� AR15 DI using commercial grade 55 gr ammo - Weight: 17.6 oz - Length: 6.44 in - Diameter: 1.6 in