The Area 419 SIDEWINDER Self Timing Brake is not just another knockoff copy of existing self timing brakes. It was engineered from the ground up to be extremely effective, easier to install, and much more versatile. The SIDEWINDER uses the same patent pending self timing technology as the HELLFIRE, only larger. Each brake includes one universal adapter. 6.5mm - Good for any bullet caliber up to and including 0.264Extremely easy installation, brake WILL NOT turn as you torque the collar to lock. No more guessing where the brake ports will line up once you tighten it down!- Simple round knurled nut that requires no tools to time the brake.- Return to zero is excellent. This means removal of your brake and re-installation will not require a zero change.- Suppressor mounts like those available for the HELLFIRE will be available soon.- Simply torque the included universal adapter onto your barrel with a 13/16a ^2 wrench, this piece never has to come off. Next, LEFT HAND thread the brake/collar assembly onto the adapter until it is almost snug. Now rotate the brake until it is level, push the brake into the adapter and you will feel it lock onto the taper. Now tighten the collar fully by hand, and you are done.