Orion 5755 RedBeam II LED Flashlight Handy red LED flashlight illuminates your telescope equipment and star charts without disturbing dark-adapted vision Adjustable brightness wheel lets you control just how bright or dim you want the red light to be Twin red LEDs are powered by one replaceable 9-volt alkaline battery (included) for up to 600 hours of use Durable 4-1/4" long plastic housing fits easily in a pocket and features a long lanyard for hanging around your neck in the field Keep your eyes dark-adapted and don't lose another set-screw in the dark with this handy red flashlight from Orion!