Here is a little run down on how brakes work and why mine are more effective.....gases from a rifle typically exit the muzzle following the bullet but dissipate rapidly when they exit the barrel because of how light they are. A muzzle brake redirects those gases to reduce the recoil. Brakes that have baffles/holes angled forward are less effective then those that are 90 degrees to the bullet travel and those that angle back are more effective then those at 90 degrees. If you squirt a garden hose into your hand with your fingers barely bent it hardly deflects the water. As you bend your fingers more it "grabs" more water. When you make a full cup out of your hand it captures the most water. Muzzle brakes work the same way. My brakes are more effective because the ports are angled back towards the shooter capturing the most gas and using it to pull the rifle forward. While no brake is really ear safe, brakes like mine, can be even harder on the ears because of how the gases/concussion are redirected. They do not change the decible level of the gun but it changes where that noise goes, like changing the direction of the water in the example above, which appears to make the brake louder. I do not recommend shooting any brake without hearing protection as they WILL cause hearing damage no matter the angle of the ports. Loud is loud and guns are loud enough to cause hearing damage without a brake. The up side to having the ports out to the side or back towards the shooter is that game animals have a harder time locating where the shot came from and many times they will run towards you. If you want to shoot without hearing protection I highly suggest purchasing a suppressor as muzzle brakes are not hearing safe.
A little info about my ported brakes......these were the first brakes I started selling. They are fairly effective, as you can see in some of my videos, but they have some downsides to them. The top holes tend to cause too much down thrust on smaller diameter sporter barrels and large capacity cases. The negatives to that is the barrel can make contact with the stock if there isn't enough clearance and it can make it harder to spot shots because it's essentially pushing the barrel past what your trying to look at when firing a shot. A lot of people seem to think ports or holes without a opposing side is detrimental to accuracy. The top holes don't have equal holes on the bottom to oppose them which causes uneven forces. I haven't noticed a difference in accuracy because of that but some believe it does cause issues.
.750 4 port brakes are available in 1/2x28, 9/16x24, and 5/8x24. I also have a few 7/16x28 brakes on hand. These are 2.5" long, weigh 2.5 oz, and are $60.00 shipped
The .875" 4 port brakes are available in 5/8x24. They are 2.5" long, weigh 3.9 oz, and are $60.00 shipped.