NOCKTURNAL LIGHTED NOCK NT502

X-SERIES RED 3/PACK FEATURES-Red-3 lighted nocks per pack-20+ hours of battery life - you can still find your arrow the next day-Can go straight from the package to the shaft in fully operational condition-Piston driven contact switch ensures LED illumination every time-Waterproof & shock resistant-Fits arrows with inside diameter of .204