I know they don't look like much, but they changed my river fishing. What you are looking at is a spider weight. They are made from copper pipe filled with 5 oz. of concrete that has smaller diameter copper wire inserted into the end. They are used by surf anglers to dig into the sand and keep the bait from being brought back to shore by the waves. It looks like this when you open up the wire (get why it's called a spider weight).
The secret is that unlike a round or pyramid weight these don't get snagged. If they get caught up on the bottom those thin wire fingers bend and free the weight. The 5 oz. of concrete help it drop quickly through the water column and they cast really well. I also like the fact that since they are significantly longer than standard freshwater sinkers you can add more weight. Just clip on your round sinkers and they don't interfere since they are shorter. In strong current or sandy bottoms they work just like they would in saltwater and dig into the bottom so can place your bait where you want it, not where the current decides to let it settle.
I rig them up just like I would any other weight for catfishing. I run the line through a weight slide, bead, and then tie on the hook.
As you can see it has many advantages and is just another tool in the arsenal available to saltwater anglers. You can find these online or make them yourself. I think they are a game changer in certain conditions when fishing for catfish and sturgeon. Give them a try in strong current and you won't be disappointed.