I think you are talking about the ones made by Ranging if so I used one for years and they worked real good but just as with your bow you need to practice with them. They are not something you can just pick up and use right the first try. I do know this even one of those kind will help more than you know and as far as my digital I never leave home without it.

Take a child hunting,for they are not only our future but also the future of hunting. Roy .