The AHM Alco S-2 Dummy Diesel Switcher Locomotive RD#621A is a 1:87 scale model in HO gauge. Manufactured by AHM/Rivarossi, this switcher features a dark gray and red color scheme, perfect for model railroad enthusiasts looking to add a realistic touch to their layout. This toy and hobby item accurately represents a switcher locomotive, adding authenticity and detail to any train collection.