The very first handgun developed by the brothers Paul and Wilhelm Mauser, the Model 1877 was a single shot breechloading pistol with a novel falling block mechanism. The breechblock, hammer and trigger assembly are made as a single unit fixed to a spring-loaded arm running underneath the barrel, with a hammer-like cocking spur on the rear of the block. When depressed, the breechblock is held open by the extractor, and it closes automatically when a cartridge is inserted. The trigger works the double-action hammer and also serves as a locking mechanism for the breech. Though an intriguing and rugged design, the 1877 was competing on the commercial and military markets not only with Remington's comparable rolling block pistol but Smith & Wesson's Number Three series of revolvers, leading Mauser to leave the pistol behind and pursue the 1878 "Zig Zag" revolver, and very few were made as a result. Blade front and fixed notch rear sights, with "115" on a number of components and the left side of the frame marked "PATENT/GEBR.MAUSER&Cie/OBERNDORFa/N/WURTTEMBERG/1876" on the left side of the frame ahead of the safety switch, a lanyard swivel on the butt and a pair of checkered grips.