SRI Casting Eggs
These are thru-wired, waterproofed and painted hi-vis yellow and they use Spro 250 Pound Swivels. They'll last until they are lost.
They are a good way to fish a Red Gill or small Cocahoe, or fly, to give them casting weight. Tie on the offering with a about 3 feet of mono or fluro and bring it in dead slow. I'm going to experiment drifting live crabs with them.