Currently, I have a lumenock, and a nockturnal. I have to say that I prefer the nockturnal. It's a little harder to turn off, but think it's more reliable than the lumenock. When I shot my buck last year, I used the lumenock and saw it light up a little ways to the deer, but seemed like mid way, it just shut off. When I found my arrow (pass thru) the light was not on.