Features: Principle: Vacuum engine uses the inertia of the flywheel to drive the piston to move, which will lower the air pressure inside the cylinder. And the flame is sucked into the cylinder and burned, and the valve is closed. At this time, a vacuum state generates a negative pressure, and the negative pressure causes the piston to continue to move to maintain the next cycle. Fully assembled, easy to use: Fire the alcohol burner, continue to flip the flywheel until the machine can run itself. No need to add water. This model can clearly show the movement of valve and piston, helping students to deeply understand the internal and external combustion engines. Ideal educational model for experimental teaching and researching. Fine polished stainless steel body, solid wood base, fine copper axes, all metal hot gas cylinder & alcohol burner, heat-resistant wick - high quality materials combine into a delicate & durable model. Nice choice as a gift. Specifications: Model: QX-ZK-01 Base Plate Size: 15 * 7cm / 5.9 * 2.7inch Item Weight: 282g / 9.9oz Package Size: 20.5 * 12 * 11.2cm / 8.1 * 4.7 * 4.4inch Package Weight: 437g / 15.4oz Package List: 1 * Engine Model 1 * Bottle 3 * Wrench 1 * Alcohol Burner 1 * User Manual(English) Note: Alcohol is not included.