The 9mm Enhanced Bolt Catch is a must have upgrade that is simple to install and improves the functionality of any MIL-SPEC compatible lower receiver. Featuring enhanced control surfaces, better ergonomics, lightweight engineering and strong billet construction.Note: Bolt catch roll pin, detent, and spring not included.Features: 8620 heat treated steel Investment cast Manganese phosphate finish Versatile modular design Oversize control surfaces Raised T-shaped heel Compatible with Norgon ambi-catch Elegant tapered control surface Skeletonized design Bold horizontal and diagonal serrations