Product assembly is complex which requires professional electrician knowledge and skills. The tools needed for installation include: welding machine, electric wrench, ratchet, diamond brush, etc... If you do not good at DIY, please ask Engineer for helping. To avoid disputes, please choose carefully. Package Included 1 x Motor 1 x Controller 1 x Motor Bracket 1 x Light 1 x Chain 1 x Electric Door Lock 1 x Flywheel 1 x Extended Shaft 2 x Connector 1 x Charging Interface 2 x Speed Control Switch 2 x Handle 5 x Plastic Insert 10 x Copper Plug 2 x Steel Plate 4 x Screws 4 x Ring Name:Electric Bike Conversion Kit Model:A18014 Specifications Fit For:22-28 inch ordinary bicycle Rated Voltage:36V Rated Power:250W Flywheel Teeth:16 Rated Speed:3300 rpm Reduction Ratio:9.78 Features -Environmentally friendly material, durable and easy to operate. -This kit is suitable for installation on regular bicycles of 22-28 inches. -This kit is not suitable for modification in special models and variable speed models. Note -Without charger and battery！！！ -Due to the manual measurement,there might be some error. -This kit is for the normal bike using single freewheel. -It can not be mounted on speed gear bike and fixed gear bike!!