This is a fantastic educational model toy, suitable for DIY model lovers, laboratory teaching aids, kids playing with puzzles, gifts, etc.Name: Stirling engine modelMaterial: SUJ alloy steel + 6061 aluminum alloy + brassSize: 185X105X150mmInner diameter of heating tube: 20mmPiston inner diameter: 16mmPiston stroke: 16mmFlywheel diameter: 64mmnote:1. Do not touch the test tube that has been roasted to avoid burns.2. Light the alcohol lamp for a long time, and the alcohol lamp cannot be touched easily to avoid burns.3.Don't touch the cotton tube with alcohol lamp when heating.packing list:1 x low temperature Stirling engine