I used to use them on deep drops. I'm not sure they help. It's dark down there and it made sense to use them. But to be honest, I didn't catch any more than anyone next to me. I had better luck with those glow in the dark necklaces they sell at night parades. I would tape them to the leader from the swivel to the live bait. I remember buying a whole box of them about 8 years ago durning a night parade. The vendor thought I was nuts. I think there was 100 to the box. They went dry after a couple of years. Don't buy too many.