Hi Friend, the stirling engine arrived very fast, but there are 2 problems, which make it unusable. 1) problem the inner glass is broken. 2) problem, the piston glass is also broken. Furthermore, the piston tightening screw is loose and has no thread to close. I would say a disaster. I paid 25 Euros for nothing !!! I send you videos and photos as you requested to your email
everything fine, beautiful, nice item