The Celestron Night Vision Flashlight uses two LED’s to provide a variable (Use the thumb wheel to adjust the light as you need it) red illumination. A red torch flashlight is one of the most beneficial and useful accessories an amateur astronomer can own. When you are outside doing astronomy, or any night-time activity that requires you to see as well as possible, any white light is a detriment. Every time you use a white light torch to see in the dark, your eyes react, your pupils contract, making their aperture smaller, and a smaller aperture always means less light-gathering, whether we are talking about your eyes or your optical equipment. A white light torch can ruin your dark-adaption.
No matter how occasional your night sky observations may be. Also, if you plan to observe with other people, whether at a star party or in your own neighbourhood, a red flashlight is an important part of good star party etiquette. Using a red flashlight allows you to see your star charts, find an eyepiece in your accessory case, or pick your way over telescope cables and other obstacles without affecting your night vision. The better your night vision, the more you can see in the eyepiece.
A useful design feature of the flashlight is its square shape so stopping it from rolling off of your observing table to the ground. A lanyard is pre-attached so you can wear it around your neck. The Night Vision Flashlight is powered by a 9V battery (included).