Scope Coat Barrel Boot Size D for AR-15 Rifles - Black. The Barrel boots keeps dust dirt etc. out of your barrel. Scope Coat Barrel Boots are available in 2 mm thickness. These Muzzle Covers are made from light-weight neoprene material Scope Coat Protective Muzzle Covers Available Colors BB-Size-D-BLUE: Scope Coat Barrel Boot Size D - Blue BB-Size-D-CB: Scope Coat Barrel Boot Size D - Coyote Brown BB-Size-D- BLK: Scope Coat Barrel Boot Size D - Black BB-Size-D-CAMO: Scope Coat Barrel Boot Size D - Camo BB-Size-D-OD: Scope Coat Barrel Boot Size D - Olive Drab BB-Size-D-RED: Scope Coat Barrel Boot Size D - Red BB-Size-D-DE: Scope Coat Barrel Boot Size D - Dark Earth BB-Size-D-NG: Scope Coat Barrel Boot Size D - Natural Gear Specifications for Scopecoat Barrel Boot Neoprene Muzzle Covers Size D: Gun Model: AR15 Features of Scopecoat Barrel Boot Neoprene Muzzle Covers Size D Heavy Barrel .22 cal & Center fire - Length: 11 Diameter: .75 to 1 12 & 20 Gauge - Length: 11 Diameter: 1 to 1.25 Double Barrel 12 & 20 gauge shotguns and Muzzle loaders - Length: 11 Diameter: 2.0 AR15 - Length: 5 Diameter: 0.75 If your rifle has a muzzle brake or compensator please account for the extra width/diameter Package Contents: Scopecoat Barrel Boot Neoprene Muzzle Covers Size D Scopecoat Barrel Boot muzzle cover is constructed of the same Neoprene our Scopecoat's and Slideboot's are. Barrel Boot slips easily over the muzzle to protect it from wear dust moisture and scratching. Barrel Boot also helps top protect the bluing. Fits long guns target ries and shotguns. Features/Specifications: Heavy Barrel .22 cal Center fire - Length: 11 Diameter: .75 to 112 20 Gauge - Length: 11 Diameter: 1 to 1.25 Double Barrel 12 20 gauge shotguns and Muzzle loaders - Length: 11 Diameter: 2.0AR15 - Length: 5 Diameter: 0.75 If your rifle has a muzzle brake or compensator please account for the extra width/diameter