Buy on Amazon.com : http://www.amazon.com/gp/product/B00M1J3A2S?tag=catfoodrevi0a-20

Neewer? 12/30cm Camera Track Dolly Slider Video Stabilization System for DSLR SLR Cameras DVs

Adjustable damping system is convenient for regulating and locking
The width of the axles are 7 from wheel to wheel
The wheels use high end roller bearings with smooth roller blade type rubber wheels
This Slider is a unique linear video camera slider is combined with adjustable axles and smooth bearing dolly wheels
The Slider can also be tripod mounted using either 14-20 or 38 threads centered under the slider