Specification:
Name: Low Temperature Hot Air Engine Model Size (Dia*H): φ89*135mmMaterial: Metal AluminumSurface Treatment: Anodic OxidationProduct Weight: 152g

Features:
1. . This low temperature stirling engine, runs on a hot cup of water (Do not put it above a candle or other fire), could be a great conversation starter at work and unique gift to families or friends or for class demonstrations. 2. It is almost ready to run: after the installation, put it on a cup of hot water or Ice water, wait about 20 seconds, gently flip the wheel,then it will run itself. 3. Basically you can run this engine up to 20 minutes with a cup of warm water (the engine must be cool). The bigger the temperature difference between the top and bottom plates the higher RPM you will get. This works best with a hot cup of water underneath and an ice cube in a plastic bag on the top (there is plenty of room for one ice cube on top). 4. Durable, well made, sytlish, and adjustable.Very fantastic craftsmanship, made with Metal Alloy. 5. If there is a little noisy, ONLY use a little graphite dry lube or a pencil quieted it down nicely. Do not use oil to lubricate,which will mix with dust in the air, and become a oil-dirt, finally make the friction to be even bigger.The stirling engine can't run smoothy.
Principle:This low temperature stirling engine,runs on a hot cup of water (Do not put it above a candle or other fire). The engine's speed depends entirely upon the temperature difference between the hot side and the cold side. In the case of using a cup of hot beverage, not only is the engine transferring the beverage's heat to the surrounding air, there are air currents constantly crossing the top (cold) plate. The differing temperatures will cause the engine to slow or speed according to the net difference between the two plates. For some extra fun, you could obtain a USB-powered cup warmer and place engine on that. After the warmer finally made it to full temperature, the engine will chug along like a champ. 
Package Included:
1 x Low Temperature Hot Air Engine Model