1.25''/ 2'' Variable Polarizing Filter Lens for Astronomical Telescope Eyepiece Features: 1.The variable Polarizing filter acts like a dimmer switch for your telescope. 2.Adjust the amount of light transmission from 1% to 40% by rotating the filter housing. 3.Reduces brightness of the Moon or planets for great clear viewing. 4.Finer control of the image brightness compared to a standard fixed-transmission telescope filter for optimal performance. 5.Fit standard sized 1.25/ 2 inch eyepieces and accessories. Descriptions: Premium Quality Metal Rim and Optics Glass Lens. Its compact, lightweight body makes it an ideal travelling companion. Specifications: Type: Variable Polarizing Filter Material: Optical glass lens + Aluminum Frame Shape: Round Barrel diameter: 1.25/ 2 inch Package included: 1 x Filter Notes: 1. Please allow 1-3 cm measure error. 2. The color of the actual items may slightly vary from the above images due to different computer screen, thanks for your understanding.