The 37mm Encoder gearmotors are widely used on Intelligent robots,intelligent manipulators, intelligent furnitures, Intelligent focusing systems etc. Those are incredibly tough and feature full metal gears. Have gear ratio 6.3:1 to 810:1,1600rpm~12rpm, stall torque 1.8~140Kg.cmType: MG37D-120047-210Features:Voltage: 6-18 VGear Ratio:210:1Stall Torque: 46.8Kg.cm (6V)Stall Current: 4.3A (12V)No load Speed: 47rpm (12V)No Load Current: 180mA (12V)Rated torque: 11.7Kg.cm (12V)Rated Speed: 37rpm (12V)Rated Current: 1.2A (12V)Size: 37*80(gearhead length 22mm)AB phase Hall Sensor Encoder 64CPR(data sheet download @12V 47rpm 210:1 Encoder motor)