For Gen 1-4 Manufactured in the U.S.A. exclusively for SureFire by ZEV Technologies, maker of innovative firearms parts and accessories, these match-grade, drop-in barrels feature extremely tight tolerances, making them some of the most precise in the industry. Every high-performance barrel is double honed (rough and finish) to achieve a minimum surface finish of 16 RA, and during this process they are held to a final dimension of +/- 0.0002" for consistency and accuracy. And because they're produced specifically for SureFire, the thread specs and profile of these barrels are perfect for accommodating a SureFire Ryder(TM) 9mm suppressor. Constructed of pre-hardened chromium stainless steel (416R)-originally designed for use in match-grade rifle barrels-these highly corrosion-resistant barrels provide high tensile strength and toughness able to withstand typical chamber pressures. Each and every barrel is cut, rifled, and 100% inspected for groove dimensions and broach finish. SureFire drop-in ZEV barrels fit Glock 17 9mm pistols and feature a muzzle thread size of A 1/2" x 28 TPI and durable Black DLC protective finish. For precision accuracy, extreme durability, and seamless compatibility with a SureFire Ryder 9mm suppressor, there's no beating one of these high-performance, match-grade pistol barrels made by ZEV for SureFire. Specifications Caliber 9 mm Twist Rate 1:16 Thread Sizes 1/2" x 28 TPI / M13.5 x 1 LHDescription Features Made in the U.S.A., exclusively for SureFire, to extremely tight tolerances for precision accuracy Fit Glock 17 9mm pistols Thread specs and profile are designed to accept a SureFire Ryder 9mm suppressor Constructed of durable, corrosion-resistant 416R stainless steel Custom thread protector helps protect barrel threads A 1/2" x 28 TPI thread size and Black DLC durable finish Backed by SureFire's No-Hassle Guarantee