The Stirling engine is a fun educational model for students and teachers. It can help you better understand the principle of operation. Characteristics: How it works A Stirling engine is a heat engine that operates by cyclically compressing and expanding air or other gas (working fluid) at different temperatures so that net heat energy is converted into mechanical work. Great explanation The teacher can greatly simplify the process of explanation, and students can better understand its principle. Safe operation Run freely on a cup of hot water, you do not need to start an alcohol lamp, safer for children. Operational requirements The initial temperature difference between the lower contact of the product and the circumstances should be greater than 25 . Easy to use Gently turn the steering wheel and then it will start working. A thoughtful project Excellent matte piston can prevent steam leakage and reduce abrasion. Do not use oil, as this will lead to oil contamination. Note: 1. Children under 12 years of age should be accompanied by an adult while playing this product Technical data: Model: LL-001 Wheel Color: Gold Material: stainless steel spray paint carbon steel glass Working principle: heating expansion / cold compression Speed: 180 rpm /min (max. ) Product Size: 12,2 * 10,2 * 10,2 cm / 4,8 * 4 * 4" Product Weight: 250g/8.8 oz Package Weight: 333g/11,7oz List of things to pack: 1 * cryogenic model of stirling motor self-assembly kit; 1 * User Manual (English)