The Angstadt Arms UDP-9 is an AR-9 firearm chambered for a 9mm cartridge. It is a compact and lightweight AR9 for CQB and tactical operations. The platform is available as a pistol or an SBR to keep it flexible and satisfy different needs. The pistol and SBR are based on the same platform, sharing many similarities, with the main difference being the buttstock, where the UDP-9 pistol features an SBA3 stabilizing brace, and the SBR features a Bravo rifle stock. The Angstadt Arms UDP-9 operates with a straight blowback action and features a 6-inch barrel, a 7075-T6 aluminum construction, a threaded muzzle with a default A2-style Flash Suppressor, an aluminum lower with a flared mag-well, and an integrated trigger guard. Thanks to its ergonomics, the UDP-9 Pistol provides excellent comfort and control. It has a B5 Systems pistol grip and a Radian Weapons ambidextrous Raptor LT charging handle. The fire control group includes an EMT-9 Trigger and a Radian Weapons Talon ambidextrous safety. As for mounting options, it features a 5.5-inch M-LOK handguard, with mounting slots at the 3, 6, and 9 o’clock positions and a continuous top Picatinny rail for mounting scopes, lights, or other accessories. The Angstadt Arms UDP-9 is available in several finishes, including a Black Hard-Coat Anodizing, Flat Dark Earth Cerakote, or Tactical Grey Cerakote finish. The dimensions are perfect for easy handling and fast target acquisition. It weighs slightly below 5 pounds and has an overall length of 22 inches. The UDP-9 is fed from a 9mm 17-round Glock magazine, accepting any aftermarket Glock magazine.