Precision Reflex Heavy Barrel Muzzle Thread Protector 5/8-24 Black. 5/8-24 Thread. Overall length is .750 and outside Dimension of .850. Specifications for Precision Reflex Heavy Barrel Muzzle Thread Protector: Manufacturer: Precision Reflex Color: Black Threads per Inch: 5/8x24 Features of Precision Reflex Heavy Barrel Muzzle Thread Protector: This muzzle protector is designed for a barrel with5/8-24 threads The protector is made of stainless steel with nitrite finish Overall length is .750 with outside dimension of .850 Package Contents: Precision Reflex Heavy Barrel Muzzle Thread Protector Precision Reflex 05-MPHB-625: Heavy Barrel Muzzle Thread Protector 5/8-24 Black