The TBAC SPIRO is a low back pressure gas-gun suppressor with excellent sound suppression at both muzzle and shooter's ear. Adds approximately 5.3 inches to weapon length. Made from Haynes 282 super alloy, stronger than Inconel 718 with higher temperature ratings, making it almost indestructible. Rated for over 20 SOCOM SURG cycles on an 8-inch barrel. Maximum rated for .223/5.56 and .22 Creedmoor. Weight 15.5 oz, Length 5.9 inches, 1.8-inch diameter. Black Cerakote finish. HUB mount version - no mount included. Note: If this product is reflected as in-stock it means it's either physically in-stock or allocated and available (serial number is assigned) at my distributor