The Yankee Hill Manufacturing .308 Thread Protector is designed to safeguard your rifle barrel threads when a muzzle device is not installed. Made from durable steel construction with precise 5/8x24 threading for .308 caliber rifles.Yankee Hill .308 Thread Protector (YHM-3415-B)5/8x24 thread pitch for .308 caliber rifles.725" outer diameter compatibilitySteel construction for durabilityProtects muzzle threads from damageEssential protection for maintaining thread integrity and preventing costly damage to your rifle barrel when muzzle devices are removed or not in use.