This impressive little single-piston steam engine works as good as it looks! It stands just under 5" tall with a 1-1/4" diameter wheel. Water is heated in the chamber (note: flame is used in operating this product). The steam pushes the piston and makes the wheel spin. The speeds it can attain are even greater than the double-piston model! Its an excellent demonstration of steam power that can fit in your pocket! Parts are made of machined brass and support parts are made of steel. The fuel source is a glass alcohol lamp with cotton wick. Fuel (isopropyl alcohol recommended) is not included. Great for the classroom or for serious hobbyists.