Choate Recoil Compensator for Mini 14 (580 Series) made of solid Stainless steel. Fits most 580 and higher series rifles. For use on rifles with adiameter of .625 barrel , 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 Mini30 rifles.