This SIG SAUER factory replacement barrel is designed for the P365 and P365-X, fitting the 3.1" slide assembly and extending to 3.7" with 1/2x28 threading for mounting a suppressor or compensator. Machined and heat-treated to Sig Sauer's dimensional tolerances, it's a genuine OEM upgrade rather than an aftermarket part, so it drops in with reliable factory-spec fit and function. The barrel retains the factory Loaded Chamber Indicator (LCI) witness hole, letting shooters visually confirm a chambered round without racking the slide. It features a black nitride finish that provides surface hardness and corrosion resistance through high round counts and sustained suppressed use. A thread protector cap is included to cover the 1/2x28 threads and keep them clean and undamaged when no muzzle device is installed. Sig Sauer P365 9mm 1/2x28 3.7" Loaded Chamber Indicator Barrel 8902059