This is what 2A Armament says :
 
 
The X4 Titanium brake is a lightweight muzzle device for large bore applications. The X4 was developed with a large initial chamber that provides a reactive surface for gasses to mitigate recoil.  The secondary chamber provides some compensating effect. The X4 was tuned to provide a softer felt impulse over traditional brakes.  The X4 Titanium is a welcome addition to any large bore rifle where weight is a concern.

Features:

    7.62mm/.308 caliber or smaller applications
    Made from U.S.A. Certified 6AL-4V Titanium
    Bead blasted for a matte finish
    Threaded 5/8 x 24 TPI for common applications
    Length: 2.75 inches
    Weight 1.7 oz
    Product of Idaho, MADE IN THE USA
    SKU (2A-TIBRAKE-X4)