1. 1.25-inch polarizing filter, made of optical linear polarizing lens 2. Suitable for viewing the contrast of lunar details and enhancing the contrast of the moon and planets in photographic images 3. With a double-piece design, of view can be gradually darkened to increase the contrast of the telescope eyepiece 4. Supports single-piece use, can be used as a daylight filter, effectively reduce light, and increase darkness 5. Suitable for telescopes with 1.25-inch interface and eyepieces with M28.6x0.6mm threads. 1.25Inch Linear Polarizer uses a high-quality anodized aluminum frame and a double-piece optical polarizing filter, which is suitable for reducing the amount of light entering the eyepiece. When observing bright objects (such as the moon or some planets), you can gradually darken of view to a certain degree, depending on your needs, while increasing contrast, reducing glare, and increasing the visible details. The 1.25Inch polarizing filter is an entry-level universal moon and planetary filter. Lens material: optical linear polarized lens Dimensions: 1.25 inches (about 31.7 mm) Thread size: M28.6x0.6 mm Net weight: 14 g Color:Black Material:ABS Package Contents: 1 x 1.25Inch Filter Variable Polarizing Only the above package content, other products are not included. Note: Light reflection 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.