LightWedge NightVision LED Booklight Patented Lightwedge technology puts light only on the page Same size as the larger LightWedge Original so it is perfect for hardcover books and maps and charts of all sizes Made for sailors, astronomers and aviators with night vision friendly red illumination 2 powerful red LEDs shine light discreetly in low-light working environments 40 hours of light from 4 AAA batteries (not included)