Features: This UHC filter is known for producing exceptionally sharp and clear images, making it one of the most popular astronomy accessories. It is suitable for both celestial observations and astrophotography. With a 1.25" barrel diameter, it easily attaches to eyepieces and comes in a sturdy transparent case. It has a standard filter thread for 1.25" eyepieces and other accessories. The sky background appears darker, and the contrast of emission nebulae is significantly improved. This filter is ideal for viewing nebulae from light-polluted skies and for enhancing contrast from dark sky locations. UHC filters, also known as light pollution reduction filters, are designed to selectively reduce the transmission of certain wavelengths of light, especially those caused by artificial lighting. The filter features an optical glass lens and an aluminum frame, effectively reducing light pollution, making it great for urban and suburban observations. Package Includes: 1x UHC Filter Specifications: Material: Glass + Metal Size: Standard 1.25 inch Diameter: 4cm / 1.57 in Note: Please allow 1-3cm difference due to manual measurement. Kindly ensure you are comfortable with this before purchasing. Due to differences between monitors, the picture may not reflect the actual color of the item.