Designed to reduce glare and light scattering, perfect for observation, allow you see the details.2 colors provide more choices to suit for moon and sun.Optical glass lens, provides clear and sharp image; Lightweight and solid anodized aluminum frame.Standard 1.25inch size,suit for any 1.25inch diameter eyepiece. Double-threaded, allow to be stacked in various combinations.Technical Specifications:Size: 1.25inch (31.7mm)Frame material: Aluminum alloyLens Material: Optical glassThread specifications: M28*0.6mmColour: black + greenMaterial: optical glass + aluminum alloyPackage Contents:1 x Green Filter1 x Black FilterOnly the above package content, other products are not included.Note: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.