This is the PR brake in 9/16x24 with a .770 OD on the brake. This is a great streamlined brake for the sporter contours out there. The ports on it are all 90 degrees which redirects the gas blast/concussion away from the shooter. Very effective brake for its size. Great for sporter contours with big enough muzzles for a 9/16x24 thread.
.770 diameter
barrel must have atleast a .620 muzzle diameter to accept this brake.