SHAS MR/DR/XR THREAD ON COMPENSATOR The NEW Shadow Systems thread on compensator is designed to interface perfectly with our existing MR920, DR920, and XR920 slide designs. The compensator will significantly improve shot-to-shot times and lessen felt recoil. Our clamping system is rock solid yet avoids the common issue of damage to the threaded section of your barrel. The conservatively designed port size ensures reliability with full power ammunition and limits muzzle blast to the sides of the pistol.