Must have if you have a 320c - SIG SAUER P320 9/40/357 Carry Grip Module Assembly

There’s not a lot of info online regarding what grip module to buy if you have a 320C, but want the 17 round mags to fit “flush”.( the OEM 320C frame fits the 15 round mag). Yes the 17 round mag will work with the off the shelf 320C grip module but it will stick out a bit. Kinda like putting a g17 mag in a g19. The large, medium, small size options refers to the “girth” (for lack of better terms) of your hand size.