True Precision Threaded 9mm Luger 1/2 x 28in Glock 19/19X/G45 (Gen 1-5) Handgun Barrel - Black Nitride - This replacement barrel has an improved overall fit from OEM with added chamfers, improved radius cuts, and other additions for a better than OEM barrel. It also has a fully supported SAAMI spec chamber. Easy To Install Drop-In Design Fits The Glock 19, 19X, And Model 45 (9mm) Pistols In Gen 1-5 Advanced Proprietary Broach Cut Design Specifically Engineered For Increased Accuracy Potential Broach Cut 6 Groove Rifling Allows For All Ammo Types To Be Used Safely, Including Cast Lead 100% Designed And Manufactured In The USA With USA Sourced Certified 416R Stainless Steel 9mm 1/10 RH Twist Rifling Special 11 Degree Competition Style Target Crown For Non-Threaded Versions Or 1/2 x 28in Threads With Included Thread Protector On Threaded Versions Threaded Versions Include Viton High Heat Integral O-Ring Lock Thread Protector