It's a threaded barrel collar. What else do you expect it to do than save your threads from getting screwed. It gets five stars cause it does exactly as intended and you can't make it do anything else. So unless it rusts to pieces with regular maintenance, it can't be improved on any further.

Revived in timely manner haven’t used it yet we’ll see.

Functions great as intended.

Lost my thread protector, this worked perfect on glock 17.

Fits my new Brownells SIG Sauer P320 9mm full-size barrel perfectly.