Please consider Gear (reduction ) motor p12 6V 60RPM as an alternative.

Pretty nice Gear Motor with dust-proof enclosure, running at 6v 60rpm. 

Specifications

• Operating Voltage: DC 2.4 ~ 6.0V

• No Load Speed: 55 ~ 70rmp

• No Load Current: 30 ~ 70mA

• Max. Efficiency Speed: 40 ~ 52rpm

• Max. Efficiency Current: 350 ~ 450mA

• Torque: 0.7 ~ 1.2kg.cm

• Stall Current: 500 ~ 700mA

• Stall Torque: 3.0 ~ 4.0kg.cm