1、Different from the traditional low temperature stirling engine design, we made this stirling engine with a square base. 2、Selected high hardness bearing steel cylinder piston, not worry about the breakage and short life of the glass cylinder piston. 3、Using aluminum alloy panel and bottom plate, through engraving and milling by high-speed machining center and anodized treatment, this stirling engine model is also an artwork on your desk. 4、Run freely on the top of a cup of hot water, no need to fire a alcohol lamp, safer for children. 5、It has a wide range of applications for children's science projects, physical/mechanical learning, teacher demonstration props, birthday gifts for friends, family, children, etc. 1 x Low Temperature Stirling Engine Item Type: Stirling Engine ModelMaterial: SUJ Alloy Steel, SUS, 6061 Aluminum AlloyItem Size: 105x105x140mm / 4.13x 4.13x 5.51inCylinder Inner Diameter: 94mm/ 3.7inPiston Stroke: 8mm/ 0.31inPiston Diameter: 16mm/ 0.63inFlywheel Diameter: 64mm/ 2.52in