The Hornby Stevensons Rocket is steam powered, being fired by butane gas which is stored in a tank inside the barrel on the tender. It runs on 3 1/2" gauge track.The model that I have is boxed and has never been run unfortunately this means that I never run it either. The box and contents are in mint condition. In addition to the loco, I have one coach. This is boxed and also in mint condition with transfers for a choice of 5 names. They are quite fragile and easily damaged.