Muzzle Brake
A device threaded onto the muzzle that vents propellant gas sideways to reduce felt recoil and muzzle rise, but with added side concussion.
A good brake can cut felt recoil 40-60% on a magnum cartridge. The tradeoff is concussion: side ports send gas and noise out laterally, which is unpleasant for spotters and bystanders.
For prone bench shooting, a brake makes spotting your own impacts much easier. The rifle stays flatter under recoil so you can watch the bullet land. For hunting or positional work, a suppressor is increasingly the preferred answer.