This is a thread protector for Q Plan B compatible muzzle devices. It also works with Rearden, Liberty Machine and other manufacturers of Plan B muzzle devices.

I recommend printing this slow with a thinner layer height, 0.12mm worked best for me. The threads will be somewhat snug straight off the printer but break in after installing a couple of times. If it's too tight after that try sizing it up in your slicer.

Disclaimer: This is intended for transport and storage uses only. It's possible to melt this thread protector to your muzzle device. Don't fire it with the thread protector attached.