This is the first year I used the Luminocks and although I bought the correct ones for my arrows I noted a problem. Now that it has gotten colder, when it is time to get out of the treestand, I un-nock the arrow and the Luminock comes off. When i get back home and everything warms back up, the nock is snug and secure in the arrow (carbon arrow). iI assumed this is due to the difference inf expansion/contraction between the carbon and the plastic. Just as a test, I put the arrow in the chest freezer for 1/2 hour and took it out and sure enough the Luminock is loose. I corrected this by putting the arrow/nock in the freezer, then placing a small strip of scotch tape on the nock and reinstalling. Now it is secure out in the field. So if you are having the same problem, here is your solution.