I had been looking for a double pinned slider (slider with two knobs , minimum and maximum) using mootools. Though , I did find a few  well done double pinned slider in the mootools forum, The only problem was that all these sliders  dint have the selected range marker.  Finally! I decided to  create my own. Well! I did use the original code  and modify it to have a slider background that indicated the range selected visually, as in my example below. The BLUE areas indicates the range of value chosen.

View Version 2.2 Demo | Download Mootools Double Pinned Slider Version 2.2 (Downloaded 4347 times)

You can very easily change the look and feel of the  range indicator ( in blue in the above example), slider knob, the slider track by modifying the slider.css as required.

Do drop me a comment if you find it useful.