The Orion Variable Polarizing eyepiece filter acts like a dimmer switch for your telescope, to tone down brightness and accentuate contrast of bright celestial objects. Gives you much finer control of the image brightness compared to a standard fixed-transmission telescope eyepiece filter for optimal performance. Adjust the amount of light transmission from 1% to 40% by rotating the eyepiece filter housing. Consists of two high-grade glass polarizing filters in an 1.25" rotating anodized aluminum cell. Threaded for use with any Orion 1.25" telescope eyepiece equipped with filter threads