Fine Workmanship : Full metal body. Made of aluminum alloy and alloy steel. Anodizing and coloring process. The surface is fine and smooth. The engine is small and powerful, one-button start. Engine kit : It is composed of hundreds of parts. The parts are processed by CNC to show the creation of human wisdom. Some parts require DIY assembly by users. Self-organized creation is more interesting. Engine Performance Speed: 2500-10500 rpm Stroke: 17.0mm Cylinder Diameter: 16.60mm Displacement: 3.5cc Power: 0.5ps. Real machinery : Highly simulated, closer to the real engine, long stroke, effectively providing higher torque. Engine use : Model cars, model boats, model aircraft and other equipment. The kit is also suitable for decoration, science and education, exhibitions, etc. size: 100.5 x 81.6 x 84.61MM Material: Aluminum alloy + alloy steel colour: black