It works as stated - Precision Armament EFAB Hybrid Muzzle Brake

I used this on a shorty 10.3, outside portions of this range are covered and have walls other portions don’t , depending on which yard line you’re at. I say this because I have heard much online chatter about loudness or concussion concerns and with this device that was not the case. I did not notice any concussion outside of what a normal 16 inch barrel produces . Now I didn’t shoot and compare back to back with a full sized rifle but I shot one before and if there is a difference I did not find it noticeable with this device. A testament that it works. I shot during the day time so cannot attest to the flash hider functionality, but during daylight I did not notice any unusual blast flame or smoke. Just felt like boring normal. Which is what I was looking for as to rid any absurd loudness or bang. So it works. Bonus is it looks great. I’d recommend it to anyone.