That it is in the hand heat-Stirling is a kit whose assembly requires some skill and a precision mechanic screwdriver was of Product description not clearly visible. With hand heat to the finished model can not drive, it requires to have a cup of hot water. The construction manual is illustrated, the text but unfortunately only English. Under Youtube there is a helpful video (English), that is very useful during assembly. Enter the search term "handheld Stirling Engine Kit Assembly" on YouTube. Overall, it seems to me the kit, as measured by the supplied parts, a bit overpriced.
