The WSR DC Gear Motor with with bult-in Encoder was designed for strength to endure competiitons.
Specification,
Voltage: 12 volts
Length: 134.1mm (5.29in)
Gear Ratios: 60:1
Diameter: 37mm (1.5in)
Torque: 700 oz-in. (504 g-m)
RPM: 100
Encoder: high-resolution Hall effect
Weight: 0.33kgs (0.7lbs)