Choate Recoil Compensator for Mini 14 (580 Series) made of solid steel, bath blued. Fits most 580 and higher series rifles. For use on rifles with a barrel diameter of .625, make sure to measure the barrel before you order, some of the early 580 series rifles have the smaller .562 barrel. The compensator is attached to the gun barrel by a 1/8 inch spring steel roll pin. Drilling new role pin hole is required. We suggest this unit be installed by a gunsmith. Also fits older Mini 30 rifles.