Choate Tool Mini-14 580 Series Cage Comp 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. We suggest this unit be installed by a gunsmith. Also fits older Mini30 rifles. Specifications for Choate Tool Mini-14 580 Series Cage Compensator: Manufacturer: Choate Tool Color: Black Country of Origin: USA Features of Choate Tool Mini-14 580 Series Cage Compensator blued steel. For .625" barrel diameter Package Contents: Choate Tool Mini-14 580 Series Cage Compensator Choate Tool CMT-07-07-23: Mini-14 580 Series Cage Comp Stainless Steel