The Katsumi HO Scale Brass AC-4 4-8-8-2 Steam Loco Southern Pacific #4101 is a vintage model train steam locomotive designed by Katsumi Scale Models. This black-colored locomotive features a 4-8-8-2 wheel configuration and is made of brass material. With a scale of 1:87, this Japanese-made model is a C-6 Very Good grade collectible for model railroad enthusiasts. Its AC power type and Southern Pacific corporate roadname add to its authenticity and appeal for collectors of vintage locomotives.