There are two basic versions of this model. Both chambered for .41 rimfire cartridge. 4-shot version is known as "Cloverleaf" due to shape of the cylinder when viewed from front. Approximately 7,500 of nearly 10,000 House revolvers were 4-shot configuration. Offered with 1.5" or 3" barrel. The 1.5" length is quite rare. Some octagonal barrels in this length have been noted. 5-shot round-cylinder version accounts for the rest of production. Found with serial numbers over 6100 and offered with 2.875" length barrel only. Model stamped on top strap "Pat. Sept. 19, 1871". Has brass frames that were sometimes nickel-plated. Barrels are found blued or plated. Grips are varnished walnut or rosewood. Slightly fewer than 10,000 of both variations manufactured from 1871-1876. NOTE: Blued models will bring a premium over nickel in same condition.