Luminoks SUCK...they are horrible. Just had them send me a replacement pack because I bought a pack of 3 and ALL three did not work. I followed every word of the directions and read every inch of their website. Its kind of sketchy when everywhereyou look it says...IF YOU DO THIS IT WILL RESULT IN DAMAGE TO THE NOCK. DONT DO THIS...DONT DO THIS...They are fragile pieces of ****. Buy the tracers.