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. - Key Benefits - 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.