True Precision Sig Sauer P365 Threaded 1/2x28 Handgun Barrel - 3.6in - Stainless - This barrel has 1/2x28 threads with included thread protector on threaded versions. It includes a Viton high heat integral O-ring lock thread protector. Easy To Install Drop-In Design 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 SAAMI Spec Chamber Improved Overall Fit From OEM With Added Chamfers, Improved Radius Cuts, And Other Additions For A Better Than OEM Barrel Assorted Specialty Coatings And Finishes To Choose From Improved Feedramp Design Over OEM For More Reliable Feeding Of Defensive Ammo