The Fishfinder slides allow your line to slide through the connection without the fish feeling the weight while the sinker remains on the bottom. . Also eliminates line fray that sometimes happens with egg sinkers.
Just feed your mainline thru the slide. After you have passed the line through the plastic slide attach a barrel swivel to the leader that is tied to your lure. The Fishfinder will keep the weight away from the lure since it cant go past the swivel. Excellent for flounder and fluke rigs!