Sig Sauer P320 M17 X-Change Kit 9mm Luger Coyote Tan The modular pistol has arrived with the advent of Sig's optional X-Change kits. Removing the P320's fire control group unlocks hundreds of combinations for your Sig pistol. The kit includes a complete slide, barrel, recoil spring assembly, grip module and magazine. The slide is reflex optic compatible and the kits are not available for manual safety.