This is the Aluminium Adjustable Rear Hub Set from TLR for their 8IGHT range of buggies & Truggies.
The TLR 8IGHT Aluminium Adjustable Rear Hub Set provides previously unavailable tuning options for 8IGHT owners. First, they are aluminium with Delrin inserts, so they still feel like a plastic hub around the track and should they show signs of wear, you can simply replace the inserts (TLR344009).
These offer 2 different hub heights with 2 sets of camber link holes. This allows you to adjust the roll center of the rear hub and have 2 options for camber link placement. TLR team drivers found that raising the hub on high bite surfaces is very helpful. In the raised or +4mm position, you can either run the camber link in what would be the normal position or you can run it the new raised position as well to increase forward grip.
These hubs include 3 different bearing inserts. The different inserts offer another tuning option. The front bearing will always use the smallest of the inserts. However, the rear bearing has 2 different inserts that can be used. There is a thicker one which is used when you wish to run the CVA or the short universal (TLR342011) that comes with the tuning kit. There is also a thinner one which is used if you wish to run the longer universal (TLR342010) so that you can now run the same length front and rear universal if you are running the optional front spindle (TLR344006) with the universals up front.