TAPCO Threaded Barrel for Glock(R) 17 - Black - Made from match grade 414 stainless steel with a black nitride finish, upgrade your barrel with the TAPCO Glock(R) 17 Threaded Replacement Drop-In Barrel. An easy-to-install barrel, simply just drop it in, no gunsmith or other modifications are required. All threaded barrels also include a thread protector. Fits Glock(R) 17 Gen 1-3 9mm Luger Match Grade 414 Stainless Steel Black Nitride Threaded 1/2 x 28 Includes Thread Protector