Glock 17 barrel: This Glock Bloodline barrel is designed to work with Glock 17 pistols, generations 1 through 4. Although this is a simple to accomplish user friendly swap, we still encourage you to consult a local gunsmith should you have any questions about installation. This barrel is rated for use with SAAMI approved, factory new ammunition. Any catastrophic damage/failure caused to product by improper installation, use of reloads, or non-SAAMI approved ammunition will not be covered by the factory warranty. Compatible with Glock 17, Gen 1-4. (NOT GEN 5 COMPATIBLE) No gunsmith fitting required. Made in the USA, the Rosco way! Specs: Barrel Length 4.49" OAL ( Non-Threaded ), 5" OAL ( Threaded ) Barrel Material 416R Stainless Steel Barrel Caliber 9x19mm Twist 1/10 RH Barrel Crown Recessed with a 50/50 surface split Barrel Finish Melonite (Electro bore polished) Rifling Pulled broach Thread Pitch 1/2 X 28 TPI (Threaded only)