An apparatus to be mounted onto a muzzle of a firearm consists of a muzzle device, a clamp, and a fastening mechanism. The muzzle device can be a compensator or a muzzle brake. The clamp and the fastening mechanism is used to hold the muzzle device against the barrel of the firearm. The muzzle device consists of a barrel receiving aperture that traverses through a structural body. When a muzzle of a firearm is positioned within the barrel receiving aperture, the clamp is pressed against the structural body so that the fastening mechanism can be used to secure the muzzle device in place. Since the apparatus does not utilize the threads located on the barrel of the firearm, the overall quality of the threads is preserved.