Track your bolts in flight and make them easier to find after sunset or in low-light conditions with these lighted nocks. Batteries are easily replaced, and the nock stays lit for hours. The carbon flat nock weighs 28 grams but add only 18 grams to the bolts overall weight. For use with 2219 aluminum shafts. Per 3. Available: Red, Green. Cancer and Reproductive Harm- www.P65Warnings.ca.gov. Type: Lighted Nocks.