Sig Sauer’s Caliber X-Change Kit allows you to convert your P320 into the M18, a handgun recently adopted by the U.S. Military to replace the M9. This kit comes with the slide, barrel, the recoil assembly, the carry grip module, and three magazines; one 17 round and two 21 round extended magazines. The M18 itself is a highly modular handgun, and can be modified to fit individual preferences. The inner frame is serialized and made from stainless steel, allowing different grip modules to be installed to fit the user’s hand size. The M18 can also be modified with a micro red dot thanks to its optics ready slide, and a 3-lug Picatinny rail enables the M18 to be outfitted with lights and lasers.