"Lube Flex" 2 piece bearing cassette.  Bearing sits between two halves so it can be removed by splitting the cassette.  From folklore at the track these were developed so the bearings could be run without seals to reduce friction but offered some level of protection from debris.  I actually don't know much about them but when I showed them to a couple of old timers at the track they knew what they were.

Anyway, they came in a box of kart parts I got as a package deal and would like to find a new home for them.

The mounting holes appear to be about 78mm or 3 inches from each other.  

One side of each cassette is drilled for 3/8-16 bolts  but each of them has a stripped hole or damaged thread.

The bearings are 80mmx40mm and spin smooth.  Two seem nice and tight and one has some play.

So bottom line I think these are very cool addition for a vintage kart or for show and tell. 

I have tried to describe as accurate as I can, if you have questions please ask.  These are sold as-is.