1/2x28 thread pitch for 223/556/22LR
Engraved on top and bottom
Crush Washer included
Muzzle Brake is CNC machined heat treated steel
Weighs 4.07 ounces
Length is 2 1/4"
Outside diameter is .93"
Listing is for one brake
Notes:
1. These brakes do not use wrench flats, so the best way to install is to run a screwdriver through the large ports to torque against the crush washer. 
 
2. The smaller engraving is on the very top of the brake (with the two small ports.) The larger engraving will be on the bottom.