Microcosm M22 Mini Brass Single-Cylinder Steam Engine For Ships & Small Models Product Features: This is a mini steam engine exquisitely crafted from brass, with a cylinder diameter of 5 mm and a stroke of 3.7 mm. A steam engine is a heat engine that performs mechanical work using steam as its working fluid. The steam engine uses the force produced by steam pressure to push a piston back and forth inside a cylinder. With its compact design, this miniature steam engine can fit in the palm of your hand, like a treasure.It also makes a meaningful gift for friends and children. Product Specifications: Model: M22 Material: Brass Color: Brass Cylinder Diameter: 5 mm (0.2in) Stroke: 3.7 mm (0.15in) Flywheel Diameter: 21.5 mm (0.85in) Shaft Diameter: 2 mm (0.08in) Product Size: 34×21×36.5 mm (1.34×0.83×1.44in) Product Weight: 47 g Package Includes: 1×Mini Steam Engine + 1×Screw + 1×Tool Packaging: Box Operation Notes: 1、The operation is simple,Simply connect it to a small boiler for normal operationand it can be installed on a small model boat or other small models,as the power source for the model.(Boiler not included) 2、Ideal for installation on model boats or other small models as the dedicated power source.