Plus 1 for lumanock, been shooting them for 2 years, only had 1 fail me so far and that was after a few hundred shots. Pulled 2 out of the closet after last season and they still lit up this season. The POI was only a bit off for me over the standard nocks that came with my arrows (Easton Axis 340) the best story i have is i spined a doe and had to do 2 more follow up shots. Had i not been using lighted nocks i would have probably lost 2/3 arrows since it got dark. I could see 3 glowing areas under the leaves in the timber and it lead me right to all 3 arrows, I was a believer after that. Losing $40 broad-heads, and Axis Carbon arrows really adds up! The nocks paid for them selves on that one hunt. In other words buy this insurance!