CALIBER 9MM & 300 BLK Subsonic - ACCESSORIES Pistons & Fixed Barrel Spacer - WEIGHT 8.8 oz - LENGTH 6.90 - DIAMETER 1.30 X 1.75 - MATERIALS Aluminum & 17-4 SS - 9MM 129.5 dB - 300 BLK SUB 128.8 dB - 45 ACP Not Compatible - Features - Eccentric offset design allows use of most factory pistol sights. - Easy indexing button feature ensures correct and repeatable orientation on any host. - Industry-leading sound reduction. - Pistons are available for common thread pitches and are interchangeable with the Omega 36M Hybrid 46M Hybrid 46 Octane Series and Omega K Series. - Can be shot wet by using 5cc of water or wire pulling gel.