Pololu - 150:1 Metal Gearmotor 37Dx73L mm 12V with 64 CPR Encoder (Helical Pinion)

This gearmotor is a powerful 24V brushed DC motor with a 70:1 metal gearbox and an integrated quadrature encoder that provides a resolution of 64

Pololu - 70:1 Metal Gearmotor 37Dx70L mm 24V with 64 CPR Encoder (Helical Pinion)

This gearmotor is a powerful 12V brushed DC motor with a 102.08:1 metal gearbox and an integrated quadrature encoder that provides a resolution of 64

100:1 Metal Gearmotor 37Dx73L mm 12V with 64 CPR Encoder (Helical Pinion)

Pololu Blog (Page 9)

Pololu - 19:1 Metal Gearmotor 37Dx68L mm 24V with 64 CPR Encoder (Helical Pinion)

150:1 Metal Gearmotor 37Dx73L mm 12V with 64 CPR Encoder (Helical Pinion), POLOLU-2828

This gearmotor is a powerful 12V brushed DC motor with a 150:1 metal gearbox and an integrated quadrature encoder that provides a resolution of 64

150:1 Metal Gearmotor 37Dx73L mm 12V with 64 CPR Encoder (Helical Pinion)

Pololu Machined Aluminum Bracket for 37D mm Metal Gearmotors, POLOLU-1995

Note: This gearmotor has been replaced by a functionally identical version with a protective end cap over the encoder.This gearmotor is a powerful 12V

19:1 Metal Gearmotor 37Dx52L mm 12V with 64 CPR Encoder (No End Cap)

Pololu Blog (Page 9)

Pololu - 150:1 Metal Gearmotor 37Dx73L mm 12V with 64 CPR Encoder (Helical Pinion)

Pololu - 19:1 Metal Gearmotor 37Dx52L mm 12V (Spur Pinion)