Griffin Technology POWERMATE USB KNOB

You can use it to edit home movies or scroll through long documents or create your next audio masterpiece. It is an assignable controller that you can program to do anything you want, in any application. Made of high-quality machined aluminum, PowerMate feels like a solid volume knob pulled right off the front of a world-class stereo. PowerMate functions beautifully as a convenient volume knob and mute button for music listening on your PC or Mac.