Chain Ring Spacers
I was doing a restoration a mid-range 1980's mountain bike whose chain kept getting stuck between two of the chainrings. I traced the problem to the original ring spacers being too wide.
Spacers are necessary when assembling a crankset to ensure proper chain ring spacing and shifting without the chain getting stuck between rings. Made by Wheels Manufacturing. Two size options available. Sold as a set of 5 spacers.