Features: Right hand extended safety for Sig-Sauer rifles Fits 550, 551, and 556 series Made from 6061 T2 aluminum Matte black MIL-A-8625 Type III Class 2 anodizing Allows for easier operation the Sig safety Mfg: Krebs Custom, Inc. SPECS: Fits Sig 550, 551 and 556 rifles. Matte black, 6061 T2 aluminum.