Between 1910 and 1926 17 units of the class HG 3/3 rack railroad locomotive were built by the Swiss Locomotive and Machinery Company (SLM) for the Brünig Railroad. The class HG 3/3 locomotive with road number 1058 was one of these units and was in service for many years, some of them on famous routes. The last 5 of the class Hg 3/3 were still in service in 1965 for freight service. The LGB model of the class HG 3/3 has a fully working rack railroad mechanism.

Like all LGB rack railroad locomotives, this model can also be used on level routes without racks. As with the prototype, the rods and the control gear for the rack railroad drive only work when the model is on a line with a rack. The locomotive has headlights that change over with the direction of travel, smoke generator, and a DCC connector for the addition of a decoder for operation on digital layouts. Suitable decoders are available at ajckids.com. The locomotive also has an encapsulated drive system with a Bühler motor and a switch for selecting the mode of operation. All of the axles on the model are powered.

Length over the buffers approximately 33 cm / 13", weight approximately 3,000 grams / 6 pounds 10 ounces.