Developed around 1915, the Haeussler pistol is a straight blowback semi-automatic using a proprietary 7.25mm cartridge and a hinged dust cover assembly for easy field stripping and cleaning. Mechanically, the pistol shows a strong resemblance to the work of Hugo Borchardt and Georg Luger, especially in the sear striker assembly, the overall shape of the frame and the grip angle. Blade front and notch rear sights, with a tapered barrel, safety switch on the left side of the frame, and "PATENT HAEUSSLER/ADLERWAFFENWERK/ENGELBRECHT & WOLFF" on the right side. With a pair of checkered grips with imprinted eagle designs, a straw finished trigger, and one magazine with a matching partial number.

Fine with 75% of the original blue finish, showing areas of brown patina, particularly on the barrel and grip straps, with bright edge wear and scattered handling marks. Bright straw colors remain on the back left side of the trigger, with a smooth gray patina on the remainder. The grips are rough, with a number of cracks and chips with the right panel mostly intact and the left 75% intact. Mechanically fine.