Sig's P320 M18 carry pistol is based on the US Military M18 model. It features an optic-ready coyote PVD slide with a removable night sight plate compatible with Romeo1PRO and Deltapoint PRO optics. The M18 also utilizes a carry length coyote grip module, ambidextrous manual safety, and a striker fire action with a short tactile reset. It includes one 17-round and two 21-round magazines.