Although identified by RMT as an Alco S-4, this locomotive is more generic than Alco. Having said that, It is a nice looking and well put together O-27 type model with a lot of interesting features such as directional lights, a flashing light on the roof and a horn. It easily pulls 5 to 6 O-27 cars but bogs down a bit if more are added. About the only complaint that I have is that it is difficult to control at low speeds using an MTH Z-1000 controller. As this locomotive is used on a dedicated loop of track, I resolved this issue by placing an 8 ohm - 20 watt power resister in series with the wire supplying power to the center rail. One more thing, the sound of the horn is kind of like a cheap bicycle horn with a dying battery. The above not withstanding, this is a good locomotive, particularly for those modellers whose interests lean toward the conventional style O-27 layout.