The RS550 (with gear teeth) DC Brush Motor Series are specially designed for rechargeable lithium electric chain saw and reciprocating saw.Features:- High-speed and high torque- High-power, low noise and long lifeParameters:- Motor type: DC brushed motor- Support voltages: 16.8V / 18V / 19.2V / 21V- Support gear teeth number: 8 / 14- No load Speed 20000-30000RPM- Rated Power: 80W (approx.)- Gear Material: All Metal- Motor Total Weight: 240g (approx.)- Motor Use Temperature: 0-50- Motor Storage:- Temperature: 0-40- Humidity: 15%-90% RHThere are 4 types of tooth shapes:- 8 teeth (8.5mm): Helical gear, for reciprocating saw- 8 teeth (10mm): Small conical gear, for reciprocating saw- 8 teeth (10.8mm): Large conical gear, for reciprocating saw- 14 teeth (8.2mm): Spur gear, for 4 / 6 inches chain sawSpecial Notes:If you want to buy RS550 14 teeth motor, there are two sizes of 14 teeth, which are used for different tools, wrongly purchase will cause the motor can't be used, please pay attention to it before order:1) For rechargeable saw, which gear diameter is 8.2mm and thickne is 9mm (this link)2) For rechargeable drill, which gear diameter is 9.5mm and thickne is 5.8mm, please click on the link below for details: Notes:Please pay attention to safety when using, disaembling and repairing power tools, and according to the product manual and take neceary personal protection measures, and keep them out of the reach of children.Package:- 1 x RS550 motor (with gear) High-precision gearsHigh strength housingPure copper coilHigh quality carbon brush Notes:1. Usually, the Motor+ and Motor- respectively connect to the DC Powers V+ and V-.2. If want to change the direction of rotation of the motor, just swap the connections, that is the Motor+ and Motor- respectively connect to the DC Powers V- and V+. RS550 Motor Brush Holder, click picture below for details.