Does anyone know what these are? They were purchased at a ham fest flea market in a bag of trimmers. Any information would be helpful.

I have no idea what the sleeves are for, but there were twice as many as the center item, so I'm assuming they are use along with it.

Thanks,
Clif

 

Circuit feed-through insulators, from one side of a circuit board to the other, some are even produced as small value capacitors in VHF/UHF/RF circuits.
Sometimes used in a metalic enclosure to transfer side to side.
Is the sleeve ceramic?
Max..