Nockturnal-H Lighted Nocks for Arrows with .233 Inside Diameter Including various Easton and Carbon Express Brands HIGH VISIBILITY and LONG LASTING LITHIUM BATTERIES - Shoot it at dusk, and with 20+ hours of battery life, you can still find your arrow the next day RELIABLE - Piston driven contact switch ensures L.E.D. illumination every time. Waterproof and shock resistant design is second to none NO ASSEMBLY REQUIRED - Nocks can go straight form the package to the shaft in fully operational condition. No prep work needed. Just insert it, and you are ready to shoot FITS ARROWS WITH INSIDE DIAMETER .233 - Including Carbon Express and Easton (see Product Description for specific Models) RED NOCK - ONE per Pack. Also Available in Green, or in 3 Packs