TenPoint Alpha-Brite Lighted Nock System - The three-piece, Alpha-Brite Lighted Nocks for Crossbow Bolts System begins with a nock-receiver insert designed to accept a combined LED unit and translucent pegged Alpha-Brite Lighted Crossbow Nocks. The nock receiver is glued into the nock-end of the arrow and indexed with the vanes.