I had no idea what those things were in the pictures Bill just posted, so I decided to do some research. Correct me if I am wrong, as I still have no idea of what I am talking about, just trying to make some connections.

http://www.pbclinear.com/Linear-Plain-Bearing...free-Liner

These are self-lubricating bearings (not sure if similar to what TPAC is making), but I noticed the Red, Blue, and Green color schemes, similar to the colors of the folders the liners are on in the tweets. It appears the colors signify some sort of standard of bearing. It also looks like the things in the tweets are what go inside the bearings, as shown in the link I posted.