This listing is for a 1/2 - 28 Threaded barrel protector. It is machined from US made steel to very high quality standards on CNC lathes in my shop. It is counter bored to accommodate a better fit at the shoulder. It has 11/16" wrench flats for easy installation. It also has a durable Black Oxide finish. Length is .750" Outside diameter is .730 With a smooth finish for a seamless look. 100% Made in the USA! Please confirm size before ordering.