Application This product is suitable for most 26-inch or 28-inch bicycles with V-shaped frames and large triangular empty frames, such as mountain bikes, road bikes, gravel bikes, beach bikes, etc. 📌(36Teeth)Specifications Material: Aluminum, Iron Color: Black, Red, Silver Style: Modern Surface Treatment: Sandblasting, Painting, Rust Prevention Shot Blasting Assembly Required: Yes Displacement: 100CC Number of Teeth: 36 Mode of Engine: Single Cylinder, Air-cooling, 2-stroke Ignition Mode: CDI Maximum Speed: 45km/28mi/h Fuel Tank Capacity: 2L/0.53gal Fuel Consumption: 2.5L/0.66gal/100km Max. Load Capacity: 200kg/440lbs Noise: About 75 decibels Fuel Number: #92, #95 Fuel Type: Mixed Fuel(16 Gasoline: 1 Two-stroke Engine Oil During Break-in Period, 20 Gasoline: 1 Two-stroke Engine Oil After) Gross Weight: 10.85kg/23.9lbs Net Weight: 9.75kg/21.5lbs Chain Guard: 41*7.7cm/16.14*3.03in Carburetor Size: 7*12cm/2.75*4.72in Fuel Tank Size: 31*18*15cm/12.2*7.08*5.9in Gear Diameter: 15cm/5.9in Engine Size: 22.5*21.5cm/8.85*8.46in Package Size: 42*42*20cm/16.53*16.53*7.87in 📌(44Teeth)Specifications Material: Aluminum, Iron Color: Black, Red, Silver Style: Modern Surface Treatment: Sandblasting, Painting, Rust Prevention Shot Blasting Assembly Required: Yes Displacement: 100CC Number of Teeth: 44 Mode of Engine: Single Cylinder, Air-cooling, 2-stroke Ignition Mode: CDI Maximum Speed: 45km/28mi/h Fuel Tank Capacity: 2L/0.53gal Fuel Consumption: 2.5L/0.66gal/100km Max. Load Capacity: 200kg/440lbs Noise: About 75 decibels Fuel Number: #92, #95 Fuel Type: Mixed Fuel(16 Gasoline: 1 Two-stroke Engine Oil During Break-in Period, 20 Gasoline: 1 Two-stroke Engine Oil After) Gross Weight: 11.05kg/24.36lbs Net Weight: 10.15kg/22.37lbs Chain Guard: 41*7.7cm/16.14*3.03in Carburetor Size: 7*12cm/2.75*4.72in Fuel Tank Size: 31*18*15cm/12.2*7.08*5.9in Gear Diameter: 18cm/7.08in Engine Size: 24*24cm/9.44*9.44in Package Size: 42*42*20cm/16.53*16.53*7.87in Package Included 1*Bicycle Engine Kit 1*English Manual All Accessories for Assembly   Notes 1.Please carefully read the manual and strictly follow the precautions to have a better experience. 2.Please note that professional installation is recommended. 3.Please note that this product requires the use of a mixture of gasoline and engine oil. During the first 500-kilometer break-in period, the ratio of gasoline to engine oil is 16:1, and after the break-in period, the ratio increases to 20:1. 4.Please note that during the running-in period, the speed should not exceed 20km/h. After the first 500 kilometers, the speed may increase to 35 kilometers per hour. 5.Please note that this product requires the use of advanced two-stroke motorcycle oil to ensure proper lubrication of the engine. 6.Please note that before adding fuel to the tank, make sure to mix fuel and engine oil, and do not add them separately. 7.Due to the need for fuel during the use of this product, please pay attention to fire safety.