My first crush washer, first time putting on muzzle device - KAK Crush Washer

I bought this to time my Birdcage properly. I put a standard birdcage on my .300 blk and this absolutely worked perfectly. I didn't even need a vice. It crushed down to the perfect timing needed.

Timing = Making sure the muzzle device is in the proper position. You most definitely need this to time your devices.