Caliber 9mm & .300 BLK Subsonic – Accessories Alpha & 3-Lug – Weight 3.9 oz – Length 4.76 – Diameter 1.37 – Materials Grade 5 Titanium & Grade 9 Titanium – Ships With Spectre 9 Tool Spectre 9 Piston Housing – dB Readings – CALIBER DB AVERAGE – 9MM 132.7 dB – 300 BLK Subsonic 133.3 dB – Features – Constructed completely out of titanium. – Designed for 9mm pistols and subguns. – Ultra-lightweight & compact for minimal impact – Full auto rated- one of the few that can run on a full-auto Glock.