The Apex Optic Mount is designed to securely mount the AimpointA(R) Acro P-1 to the slide of the Sig Sauer P320 Legion, M17/M18 and other models featuring the PRO slide cut (Rev 2). The Apex Optic Mount is machined from a billet of heat-treated steel and black Melonite finished for enhanced durability. Expected Results: Designed to fit the slide of the Sig Sauer P320 with a PRO slide cut (Rev 2) Works with the M17/M18 models with the factory Loaded Chamber Indicator Securely mount the AimpointA(R) Acro P-1 to the slide Applicable to What Guns: Works on the Sig Sauer pistols with a PRO slide cut (R2) including the P320 XFIVE Legion, P320-M Mfg: Apex Tactical Specialties Inc