Lumenok CrossbowNock HD Orange Excalibur Flat 3 pk.. Lumenok CrossbowNocks are the only lighted crossbow nock that is activated by the force of the string on the shot and deactivated by slightly pulling the nock away from the arrow shaft. Lumenok Crossbow Nocks provide a bright aiming point on the arrow's rear broadhead - so bright in fact that it temporarily blinds any unsighted animals. Give yourself the advantage of a lightning-fast bolt recovery as well - your bolts will always be easy to find. To use simply slide the Lumenok Crossbow Nock onto the back of your carbon bolt insert the lighted nock and release the forward pressure on the string. The lighted nock will activate and deactivate with the force of the string on the shot. For use in Excalibur carbon bolts with a .3015" inside diameter. Specifications for Lumenok CrossbowNock HD Orange: Manufacturer: Lumenok Color: HD Orange Quantity: 3 Pack Package Contents: Lumenok CrossbowNock HD Orange Lighted crossbow nock offers the shooter the ability to see shot placement and make bolt retrieval easier. Nock is activated by the force of the string on the shot and deactivated by slightly pulling the nock away from the arrow shaft. For use in Excalibur carbon bolts with a .3015 inside diameter.