The military-chosen Mk13-SD is an ultra-lightweight, fast-attach, high performance sound and flash suppressor engineered for bolt action rifles chambered in 300 Winchester Magnum and 7.62 x 51 mmGrade 5 Titanium monolithic baffle core and Grade 9 Titanium tube give the Mk13-SD an improbable weight of 15 ounces, and the durability to withstand the 300 Win Mag muzzle pressures and temperaturesSmall size and light weight, it delivers greater sound reduction and accuracy than any similarly-sized competing model. NSN: 1005-01-599-7024NOT FOR USE ON SCAR 17 OR RUGER SCOUT. Mounts NOT included.Specifications: Caliber: 300 Win Mag, 7.62 x 51mm Weight: 15 ounces Length: 9.5" (7.8" added) Diameter: 1.5" Finish: CeraKote Materials: Grade 5 & 9 Ti Reduction: 28-33db* S.P.L: 137-142db*