Era-Tac 57050-series Picatinny rails are engineered for an ultra-precise fit to the receiver, achieving maximum accuracy potential. They attach via Torx screws, are fully-machined from solid, high-grade aluminum, and are Type-III anodized (black), rendering them corrosion-proof. The perfect solution to providing a solid, stable purchase for a good set of rings or 1-piece optic mount on your long gun. ERATAC Picatinny 145mm Aluminum Rail Mount for Mauser M12 57050-002L