I've been missing my fiber optic for my 40 yd pin since last year. I really haven't seen myself taking a 40 yd shot in low light so I've just let it go. I can see the pin ok in good light without the fo. But it nags me so I finally put one in tonight and could not believe the difference between it and the others. It's gotta be at least twice as bright. So, since they come in a pack, I replaced all the others. I bet this gives me 10 more minutes in a tree in the afternoon/evening. That could be huge!