Orion 5562 2-Inch Variable Polarizing Eyepiece Filter A dimmer switch for your telescope! Helps to tone down brightness when viewing the Moon and planets to both optimize the view and reduce bright glare Reduced brightness and glare unmasks detail in your viewing subject and greatly improves contrast Adjust the amount of light transmission from 1% to 40% by rotating the eyepiece filter housing The filter has an anodized aluminum cell, which threads into the barrel of any 2" Orion eyepiece Foam-lined hard plastic filter storage case included