A Compensator is a firearm attachment which improves weapon stability during repeated or automatic fire by venting gases upwards. This counteracts the potential of the muzzle to flip to either side. As a consequence the visible flash of the weapon may be even greater than without a compensator.
The Compensator is a barrel attachment featured in Battlefield 4. It improves stability while having no effect on vertical recoil. The spread of automatic fire is increased when using the compensator. It is especially useful on weapons with high side-to-side recoil.