ACW Low-Profile Thread Cap Protector 1/2x28 Black Threaded Saver 9mm/357SIG/22LR Can be removed or inserted into the slide without removing the thread protector Protects 1/2x28 threaded 9mm/357/22LR barrels Melonite QPQ coating for increased wear resistance and heat resistance 5/8" outside diameter; .40" in length 100% Made in USA and guaranteed to be top quality