FEATURES-Activated upon the shot & relies upon the conductivity of the shaft-No switches or magnets required-Designed to be used over and over to allow archers to follow the pathc of their arrows-Provides up to 40 hours of illumination-Fits Easton/Beman carbon crossbow bolts-3/pack-OrangePRODUCT SPECIFICATIONS:Dimension 0.70 X 2.70 X 5.10Height 0.7000Width 2.7000Length 5.1000COLOR REDTYPE NOCKSMECHANICAL NFIXED NGRAIN 29DIAMETER .297" IDOTHER FEATURES: SIMPLE PREPERATION OF ARROW SHAFT PRIOR TO INSTALLATION WILL INSURE TROUBLE FREE OPERATION.AIDS IN TUNING,STAYS LIT UP TO 40 HOURS FITS:EASTON POWERBOLT,BEMAN THUNDER BOLT & TENPOINT PRO- ELITE