High Contrast UHC Filter reduces light pollution to improve contrast for observing in urban and suburban skies. It helps reveal faint deep-sky objects that are typically washed out by city lights. Diameter: 1.25 in. Easily attaches to standard eyepieces and fits fixed housing setups. Optical quality: The filter uses a double-sided fine polishing process to ensure smooth, precise optical surfaces for reliable performance. Substrates: Precisely polished substrates with tight parallelism and surface accuracy to maintain consistent image quality. Compatibility and use: Designed for 1.25 inch eyepiece systems, providing durable, reliable performance in common telescope setups. Use scenarios: - Urban stargazing: observe emission nebulae and other faint targets more clearly in city environments. - Suburban skies: enhance contrast for nebulae, galaxies, and star clusters during night observations. - Educational or outreach sessions in light-polluted areas, delivering clearer demonstrations of deep-sky objects.