Specification: Main Material: Stainless Steel + Aluminum Alloy Cooling Method: Air Cooling Heating Tube Inner Diameter: 20mm Piston Stroke: 16mm Flywheel Diameter: 65mm Fan Diameter : 102mm Bearing Model: Precision F684zz Features: 1. High Speed and Stability 3.F684zz Engine Motor Model Stainless Steel with Air Cooling System High Speed. Main Material: Stainless Steel + Aluminum Alloy. Heating Tube Inner Diameter: 20mm. Take out the Alcohol Lamp and Add Medical or Industrial Liquid Alcohol with an Alcohol Content of More than 95% (Not More than 2/3 of the Container). Be Careful Not to Fill It Completely. Ignite the Alcohol in the Alcohol Container, Heat It for About a Minute, and Start the Flywheel by Hand Until the Machine Runs. Oil Filling Is Prohibited in Machine Cylinders, Pistons, Bearings, Connecting Rods and Other Active Positions. During the Heating Process, Do Not Touch the High Temperature Parts of the Machine to Prevent Burns. Before Placing the Machine on the Table for Heating, Please Place Wet Wool Between the Table and the Machine to Effectively Insulate the Heat and Reduce the Vibration of the Machine. When the Machine Is Running at High Speed, There May Be Vibration and Displacement, Please Prevent the Machine from Falling from the Desktop. Please Allow 1-3cm Differs Due to Manual Measurement. Due to the Different Display and Different Light, the Picture May Not Reflect the Actual Color of the Item. Feedback is very important to us. It is impossible to address issues if we do not know about them! Faction is our ultimate goal. We work hard to earn your trust and future business. A If you receive a defective item, you may return it or ask for a discount. Due to time zones, our reply to your questions may not be immediately. If it's non-workdays, please kindly be patient and wait till Monday. Stainless steel + aluminum alloy. This item is in the category "Toys & Hobbies\Models & Kits\Tools, Supplies & Engines\Engines". The seller is "gertaingrid" and is located in this country: US. This item can be shipped to United States.