Motor with 37 mm diameter and 65 mm length, 10:1 metal gear, 12 V operating voltage, 0,2 A to 5,5 A power consumption, 1000 RPM speed, 4,9 maximum torque and 64 CPR encoder. Pololu 4758

These aluminum gearmotor brackets let you securely mount Pololu’s 25D mm metal gearmotors to your project. The brackets are sold in pairs, and each bracket includes two M3 screws for securing the motor to the bracket. Each bracket also features seven mounting holes and twelve mounting slots for M3 or #4-size screws (not included), giving you a variety of mounting options.

Motor with 37 mm diameter and 57 mm length, 150:1 metal gear, 24 V operating voltage, 0,1 A to 3 A power consumption, 68 RPM speed and 56 maximum torque. Pololu 4687

A 10-pack of adapter boards with 2-pin JST SH-type back-entry connectors for Pololu single-shaft micro metal gearmotors. Enables easy, quick, and clean wiring in compact electronic and robotic projects. Pololu 5097

Pololu low-power miniature engine, with a 15:1 transmission, shaft speed is 1400 rpm, torque is 0.2 kg * cm (0.02 Nm). Pololu 4783

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

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

Pololu - 1524

Bipolar stepper motor powered with a voltage of up to 12 V and a maximum current of 400 mA. SparkFun ROB-10551

These universal aluminum mounting hubs allow you to mount custom wheels and mechanisms to 8 mm diameter motor shafts. The set includes two hubs, four M3 set screws for securing the hubs to motor shafts, and one 1.5 mm Allen wrench for use with the set screws.

Pololu Universal Aluminum Mounting Hub for 6mm Shaft, M3 Holes (2-Pack)

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

Solarbotics GM8 143:1 Gear Motor Offset Output

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

This gearmotor is a miniature high-power, 6 V brushed DC motor with a 986.41:1 metal gearbox, making it a great choice for applications requiring fine control at very low speeds. 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.

Motor with 20 mm diameter and 44 mm length, 100:1 metal gear, 6 V operating voltage, 0.15 A to 2.9 A power consumption, 140 RPM speed and 5.4 kg*cm maximum torque. Pololu 3454

A set of adapters (adapter) from the popular 4 mm to 12 mm motor shaft, wheel holders from RC models. Pololu 2684

This gearmotor is a miniature high-power, 6 V brushed DC motor with long-life carbon brushes and a 4.995:1 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.

Flexible shaft coupling with a diameter of 8 mm and 10 mm. It is made of aluminum, has a diameter of 25 mm and a length of 30 mm

Motor with 25 mm diameter and 65 mm length, 20,4:1 metal gear, 6 V operating voltage, 0,25 A to 2,4 A power consumption, 290 RPM speed, 2,4 maximum torque and 48 CPR encoder. Pololu 4823