9mm M13.5×1 Left Hand barrel Thread protector. It is machined from stainless steel to very high quality standards on CNC lathes in my shop. It is designed for metric threaded barrels.
It will fit Glock , Heckler and Koch, Beretta and more.
Length is .525″
Outside diameter is .640 With a clean crisp knurl.
Please confirm your thread size before ordering.