10 pack of steel crush washers in black oxide finish for single use only.

1/2 x 28 thread for .223 / 5.56

5/8 x 24 thread for .308 / 7.62

Place on Barrel, prior to installing other accessories for proper timing, and centering accessories on barrel.

Crush Washer, along with a bit of metal grease properly centers and indexes your barrel accessory. Just place on the barrel, then thread on your accessories onto barrel. Quality stainless steel construction can be used either together with or instead of peel washers.

Specifications:

• Industrial Grade Steel
• Heat Treated for durability of metal
• Precisely construction for proper thread timing
• Black Oxide Finish prevents corrosion or rust