usmile Low Temperature Stainless Steel Stirling Engine Education Toy Model Run Off the Temperature difference 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.It is almost ready to run: after the installation, put it on a cup of hot water or Ice water, wait a couple of seconds, gently flip the wheel,then it will run itself. 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). Durable, well made, sytlish, and adjustable.Very fantastic craftsmanship, made with Metal Alloy 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. Size: 102 X 102 X 125mm ,Material: Steel and Glass,Weight: 236g