This Sig Sauer P320 Compact Medium Grip Module is a genuine factory replacement part specifically engineered for Fire Control Units chambered in .45 ACP. Finished in a standard black polymer, this "Medium" circumference frame provides a balanced, ergonomic grip suitable for most hand sizes and is designed for use with compact-length slides. The module includes a pre-installed, reversible magazine catch, ensuring it is ready for immediate installation into your P320 or P250 setup. Please be aware that this frame is not compatible with 9mm, .40 S & W, or .357 SIG components due to the unique dimensions required for the .45 ACP caliber. Sig Sauer P320 .45 ACP Compact Medium Black Pistol Grip Module Assembly GRIP-MOD-C-45-M-BLK