One thing you may want to watch about the Nockturnals... on the first one I tried, at least, the plastic appeared to be much softer than any other nock I have tried.
I had one set up as my #1 arrow for a recent hunt, and liked what I was seeing from it. The second evening of my hunt, though, I drove to out to a parking spot, walked through the timber with my gear, and finally sat down in an impromptu natural ground blind.
When I took the #1 arrow from my bow quiver and slipped it on to the string, I looked down and saw the Nockturnal was badly bent, or warped, or SOMETHING! It looked like the tip of the nock was almost 1/4" out of line with the rear of the shaft! It almost reminded me of a dislocated finger in appearance, or something of the sort.
I bent it back manually with little effort, but did not trust it for hunting until I looked it over more closely. Put it back in the quiver and returned to my Easton G-nock arrow.
Back in camp, I saw that it still looked slightly "askew," so I set it aside for the duration of the trip.
When I returned home, I finally got around to looking at it again. I tweaked it a second, and then a final third time, and it appeared perfectly straight. I shot it at my target and around the yard with a judo point, and it flew perfectly. But... it would no longer light! I had tried it a half dozen times before my hunt, and it worked perfectly, both on and off.
I don't know what I did that caused the bend, and do not know if that incident caused damage to the light (or perhaps turned it on, unnoticed).
Just thought it would be worth mentioning to my friends here as a precaution. I have another one to try, but will be watching closely for function and durability. It may take a little while before the product has my confidence as before, though.
I imagine the fault is mine, but it sure could have made for a sad hunt...