BREAKAWAY PIVOT BEADS
Breakaway Pivot Beads were the start of the cascade type rigs. Some clips have a bait clip on so can be relayed, all clips have a line store to take up slack so the snood can fit snugly into the clip below.
The line store can also allow for a hook change. Although these have been superseded by the cascade swivel I find them useful for night time fishing and for larger baits as they are not as fiddly as the cascade swivel.