Manufactured as a military "M18" version of SIG Sauer's P320 line of striker-fired, semi automatic pistols, which were adopted in 2017 by the United States Marine Corps, Air Force, and Navy to replace the Beretta M9 series. The design was selected for its modularity, due to the use of a serialized fire control unit (FCU) which can be readily swapped between grip modules of differing size. The slide is marked "SIG SAUER M18" on the left as well as having the military "MFR: 6ZWB1 PN: 13067088-1" markings above the takedown lever, along with a "TC" prefix serial number only found in U.S. military contract production. Fitted with a set of SIG night sights with the rear sight attached to the optics mount cover. The manual safety equipped FCU is fitted with an "M" size grip module. This pistol is still sealed in the original blue plastic factory wrapper. Includes original box with end label marked "SIGP320M18" and dated "09-JAN-2023," a "P320-M17/P320-M18" user's manual, and two sealed 21 round magazines.