Product: 12V RS550 35000RPM motor gearbox Voltage: 12V Power: 45W Shaft Hole Diameter: 20mm (0.79"); Length: 200mm(7.87") Advantage: 1. Using High-Quality Composite Materials, The Hardness Increases By 80% Compared To Ordinary Plastics 2. Both Internal Gears Are Made Of Steel, Extending Their Service Life By 75% 3. High Quality Motor, Pure Copper Winding Coil, Extends Motor Life, Increases Torque And Speed Be Careful: 1. Please Use A Reasonable Power Supply Voltage 2. Strictly Compare The Original Gearbox Size Before Purchasing 3? Please Note That There Is A Plastic Support Brace At The Bottom Of The Gearbox, Please Make Sure That The Bracket Does Not Affect The Installation Or You Can Use Tools To Modify It