The Nockturnal Launchpad Crossbow Nock is easy to install, easy to use, and specifically engineered to light up every shot with high-visibility LEDs.Features3 lighted nocks per packEach nock weighs approximately 30 grainsAdjustable colletNote:Black Collet Fits: Carbon Express, Easton, and other carbon bolt sizes with 0.284" interior diameterGray Collet Fits: Beman, Black Eagle, Bloodsport, GoldTip, Victory, and other carbon bolts size with 0.296" or bigger interior diameter