A very nice engine that runs on the heat of your coffee, tea or hot chocolate. The connections are more robust than similar engines. Overall it is a very nice gadget for demonstrating work from heat.
This Stirling Heat Engine arrived promptly and worked perfectly right out of the box. The Stirling Engine's importance in future space exploration cannot be overstated given the significant NASA investment in the technology.
You don't even need a cup of coffee or ice heat source. It ran off the heat of my hand 3 minutes after I removed it from the packaging. I held it in my hand while I was reading the brochure that came with the engine, and it started spinning!! Good job!!! It's very well made, but remember it is very delicate.