Untitled by
Hz-C, on Flickr
This is an Infinium crossfader.
There are many like it, but this one is mine.
The screw type thing on the fore is a magnet, screw it clockwise (in) and the friction (magnetic) is greater anticlockwise and it gets less so until it can freely go side to side when tipped.
The red structure that clamps the bars is some kind of self lubricating material.
Untitled by
Hz-C, on Flickr
in the middle you can see a barcody type print, this is the optical reading reference, for the optical pickups inside the spacey silver domes.
If someone has tried to "make things better" with contact cleaner or get the fader sliding with lube, it'll just screw the readings up - compresssed air probably wont shift lubricant after that point, and the only remedy is to take things apart and clean with lint free cloth and shoot the owner of the lube spray. Warranties may be affected, but it worked for me,