This Sig Sauer P320 Full Size Medium Grip Module is a genuine factory replacement part finished in a standard black polymer. It is designed to house P320 or P250 Fire Control Units in 9mm, .40 S & W, or .357 SIG that do not require a manual safety cutout. The "Full Size" length features a full-length rail for 4.7-inch slides and a full-size grip for maximum magazine capacity, while the "Medium" circumference offers a balanced, ergonomic profile for most hand sizes. This assembly comes ready for immediate installation and includes a pre-installed, reversible magazine catch.