365Astronomy Variable Polarising Filter 1.25-inch
1.25" Variable Polarizing Filter Set of Two Polarizing Filters
This set of two 1.25" polarizer filters reduces reflected polarized light in the Earth's atmosphere.
Also helpful for splitting binary stars by reducing glare and diffraction around the brighter star of the binary pair. On moon and planets it is invaluable for reducing irradiation and glare.
The effectiveness of the filters depends on several factors, including: the aperture and focal length of the telescope, the magnification being used, and seeing conditions.
The transmission level can be varied between near zero and near 100% by rotation of the two filters.
One filter can be unscrewed from another and those can be used separately as simple polarising filters just as well as they both have a standard 1.25" male and female filter threads, so can be screwed into any standard 1.25" eyepiece.