dmtrs

Hello there, This is my first topic on this forum and feel good to be around. I am looking to start a project of a MIDI controller. The key "component" of the project would be faders and I would like to understand technology behind this part and be able to find suppliers. I have been reading a post from djtechtools on faders, but I was unable to understand the "keywords" if I may to look for the type of fader I am interested in ( the ones that skates along rails whilst conductive prongs stick out and tickle the conductive track). Could I get some insight on this? On the other hand, where do you people get your faders from? Is there any supplier you can recommend. Thanks in advance, Dmtrs