Nockturnal’s unique, patented, string-activated, linear switch with piston-driven assembly ensures activation of the LED bulb every time. Nockturnal® Lighted Nocks feature super-bright LEDs and long-life lithium batteries for superior illumination that lasts. These specialty nocks perform with exceptional accuracy when shot from both vertical and crossbows. Nockturnal® Lighted Nocks blaze down range with extreme brilliance