Ultimate Arms Gear Pistol Handgun Black Phosphate Coated Steel Thread Protector Cap Made in The USA For 1/2"x28 TPI Thread Pattern 9mm Glock 17 19 26 31 34 .357 Bore & Smaller Designed to Protect Barrel Threads when not using a Muzzle Brake or and Device. Machined from Black Phosphate Coated Steel and Knurled for a Positive Grip to Assist in Installation and Removal. Dimensions: 0.69" Diameter x 0.46" Long. Weight: 0.4oz. Small & Compact Highly Effective. Designed in and Made in USA with USA Steel!