Miniature, 6V brush DC motor with metal gear and 15.25:1 gear ratio. It has a cross section of 10 × 12 mm, and the D-shaped output shaft with a length of 9 mm and a diameter of 3 mm. Pololu 4785

Pololu high power miniature motor with carbon brushes. 75:1 gear motor, shaft speed 450 rpm, torque 1kg*cm. The motor has an extended shaft, which makes it easy to attach the encoder. Pololu 3051

Add quadrature encoders to your 20D mm metal gearmotors (extended back shaft version required) with this kit that uses a magnetic disc and Hall effect sensors to provide 20 counts per revolution of the motor shaft. The sensors operate from 2.7 V to 18 V and provide digital outputs that can be connected directly to a microcontroller or other digital circuit.

This gearmotor is a miniature high-power, 6 V brushed DC motor with long-life carbon brushes and a 297.92:1 metal gearbox. It has a cross section of 10 × 12 mm, and the D-shaped gearbox output shaft is 9 mm long and 3 mm in diameter.

Pololu - 1524

Motor with 20 mm diameter and 46 mm length, 313:1 metal gear, 6 V operating voltage, 0.15 A to 2.9 A power consumption, 45 RPM speed and 13 kg*cm maximum torque. Pololu 3721

15:1 Micro Metal Gearmotor. Pololu 4782

This gearmotor is a miniature high-power, 12 V brushed DC motor with long-life carbon brushes and a 75.81:1 metal gearbox. It has a cross section of 10 × 12 mm, and the D-shaped gearbox output shaft is 9 mm long and 3 mm in diameter.

A small motor with a metal gear ending with a shaft with M3 thread, rotation speed 50 RPM, operating voltage 6 V. GA1036-N20M-0053

DC motor with hollow dome. Features a compact and lightweight design, making it ideal for applications requiring small size and low weight

A small motor with a metal gear ending with a shaft with M3 thread, rotation speed 300 RPM, operating voltage 6 V. GA1036-N20M-0057

Motor with 37 mm diameter and 54 mm length, 50:1 metal gear, 24 V operating voltage, 0,1 A to 3 A power consumption, 200 RPM speed and 23 maximum torque. Pololu 4683

This gearmotor is a miniature high-power, 12 V brushed DC motor with long-life carbon brushes and a 100.37:1 metal gearbox. It has a cross section of 10 × 12 mm, and the D-shaped gearbox output shaft is 9 mm long and 3 mm in diameter. This version also has a 4.5 × 1 mm extended motor shaft.

Key specs at 12 V: 320 RPM and 100 mA with no load, 30 oz-in (2.2 kg-cm) and 0.8 A at stall.

A complete drive in the form of a 100 mm diameter wheel integrated with a PMSM motor and controller. It communicates via RS485 bus and offers feedback information such as temperature, position, speed and current consumption. Waveshare DDSM115

AB two-phase pulse wave, measured by two infrared reflective sensor. These two sensor pulse waveform is close to a phase difference of 90 degrees, through the AB two-phase lead and lag of the waveform judged wheel forward rotation or the reverse. SEN0116

50:1 Micro Metal Gearmotor HP with Extended Motor Shaft

Small metal gear motor, 1000 RPM speed, 3V operating voltage. GA12-N20-0009

Copper alloy traveling nut intended for use with Tr8×8(P2) threaded rods and features a mounting flange with four holes threaded for M3 screws. Pololu 2688

Motor with 20 mm diameter and 44 mm length, 156:1 metal gear, 6 V operating voltage, 0.15 A to 2.9 A power consumption, 91 RPM speed and 7.9 kg*cm maximum torque. Pololu 3456

Fan module with DC motor, propeller and connection cable. DFRobot DFR0332