The Micro Gear Motors by Ever-power provides hobbyists and robotics enthusiasts with a cost Drive Chain 
effective solution to their motor requirements. The micro gear engine is capable of providing up to 1650g. cm of torque; with this kind of a little size, these fantastic little motors hold their very own against complicated and demanding tasks. Take a glance under the specifications tab for more information on purchasing and torque/rpm figures.
Also available may be the MB7 Bracket, which is featured in one of the product images and can make mounting the gear motor a simple task, requiring just two screws to attach the assembly on your application.
All of the micro steel gearmotors possess the same physical dimensions, so one version can be quickly swapped for another if your design requirements change.
Long (9mm), 3 mm-diameter D-shaped metallic output shaft.
4.5mm long, 1mm diameter back again shaft, great for optical encoders!