This is an HK HK45 Tactical semi-automatic double action pistol in .45 ACP caliber. It has a 5" threaded barrel, adjustable rear sight, front night sight, light rail, ambi-slide release, ambi-safety/decocker, amnbi-mag release, interchangeable backstrap, and 10-round magazine capacity. This pistol is in VERY NICE condition in the original box with manual, cable lock, two backstrap inserts, spare O-rings for the barrel, and two magazines.