These stainless steel shaft couplers allow you to couple two size shafts together. They can be used for connecting motor shafts to drive shafts, or two different-sized shafts. These shaft couplers have a length of 0.75”, a outer diameter of 0.42”, and couple 1/4” to 4mm shafts.
[Actobotics](https://www.sparkfun.com/pages/Actobotics) is a robotics building system based around extruded aluminum channels, gears, precision shafts, and ball bearings. Thanks to the two standardized hole patterns, nearly all Actobotics components can be intuitively connected together. The wide range of components makes building complex electromechanical prototypes or finished projects a reality.
* Length – 0.75”
* Diameter – 0.42”
* Bore A ID – 1/4”
* Bore B ID – 4mm
* [SketchUp Part](http://cdn.sparkfun.com/datasheets/Robotics/Actobotics/625118.skp)
* [Product Page](http://www.servocity.com/html/set_screw_shaft_couplers.html) (625118)