This unit replaces the magazine base plate on the SIG P365X/XL (12 round/10 round magazines). Does not alter the capacity of the magazine. Features: It adds approximately 1/2" inch additional gripping surface as well as enhanced ergonomics. The enhanced griping surface also incorporates a texture which closely matches the frame of the firearm. Made from High Impact Polymer and withstand drop tests at temperatures from -20 F to 250 F.