Description: These standard gearmotors are incredibly tough and feature full metal gears to help you drive wheels, gears, or almost anything else that needs to turn. They have a gear ratio of 3000:1 and operate up to 12 volts and deliver a stall torque of 2995 oz-in. and a max speed of 1 RPM. Each standard gearmotor sports a 6mm diameter D-shaft.
Based on 2 ratings:
Documentation on line is a little lacking of mechanical dimensions but motors perform as stated and arrived on time.