The O-27 EMD SD-9 Southern Pacific #5601 with Protosound running is a ready-to-go pre-built model replica of an Electro-Motive Diesel (EMD) locomotive. This vintage collectible features a black color scheme, sound function, and is part of a three-rail system. Made of plastic and diecast materials, this O gauge model is designed for adult collectors aged 17 years and up. With its detailed features and historical significance as a Southern Pacific locomotive from the 1990s, this MTH brand item is a unique addition to any model railroad collection.