Since I no longer have the opportunity to build it, I'm offering a significant price reduction. How about it for a winter vacation project? Initially 20,000 yen → 19,000 yen → 15,000 yen → 13,000 yen Tokyo Meter Co., Ltd. Stirling Engine Model Model: SEM-01 The instructions have only one page for assembly, followed by mechanical drawings for each part. I think even children can assemble it, and junior high school students and older can do it alone, but elementary school students will need an adult to help. After assembly, the heating part needs to be heated with a gas burner for operation. A gas burner is not included, so please prepare your own. A burner used for searing at a conveyor belt sushi restaurant will work fine. Since you will be using fire, you must be careful of burns, fire, etc., during the experiment. Before assembly and test runs, you should properly learn how to use the tools and receive safety training. Especially, the test run and experiment using a gas burner must be conducted by an adult who is careful about safety. Please note that we are not responsible for any losses, injuries, or fires that may occur during assembly or experimentation, so please purchase only if you agree to this. Unused and unassembled. The assembly precision is as expected from a Japanese company that prototypes machines; if assembled correctly, it should work. It even has small bearings, which made me feel that it was developed by a mechanical engineering company. I think Japan still needs new employees who find this kind of assembly interesting. I was glad to see that many people who were always on their smartphones found it interesting to assemble. I once did this as part of new employee training, having the young employees assemble it. The one I had, I gave to a new employee, so I bought this one thinking I would assemble it in my old age. However, I am about to retire, and my wife will be furious, so I am cleaning it up. I checked the purchase history, and the list price was 72,000 yen. Shipping will be from Monday to Thursday.