Angstadt Arms makes pistol-caliber carbines and AR-style platforms in the United States. The UDP-9 is a compact 9mm carbine on an AR-15 pattern with a direct blowback system. The MDP-9 uses a roller-delayed blowback system for reduced recoil and smoother operation. Both models accept Glock-pattern magazines and feature M-LOK handguards and Picatinny rails for accessory mounting.