Key benefits Improves image contrast between nebulae and the starry sky, helping you reveal nebula details with clearer definition. Built from durable, practical materials for longlasting performance and reliable telescope use. Easy installation with Britishthread compatibility; the back is threaded for direct screwin into compatible eyepieces. Nanoscale coating provides resistance to temperatures and helps prevent coating degradation, maintaining performance in demanding observing conditions. Specifications and features Size: 25 inch UHC filter Materials: Durable, practical construction designed for longevity Compatibility: Britishthread filter compatibility; threaded rear for direct screwing into compatible eyepieces Coating: Nanoscale coating offering temperature resistance and improved coating durability Use scenarios Visual observation in darksky environments: Use the filter to enhance contrast between nebulae and the background sky, making faint nebular structures more visible through the eyepiece. Suburban or lightpolluted observing: The UHC filter helps suppress sky brightness, allowing nebulae to stand out more clearly and aiding in feature recognition. Quickinstall observing sessions or imaging: With its straightforward Britishthread fit and screwin design, the filter can be rapidly deployed for onthespot nebula enhancement during observing or imaging setups.