1. PRECISION OPTICAL GLASS: This diagonal mirror is crafted with quality optical glass that ensures light transmission and image clarity, making it an essential upgrade for refractor telescopes and astronomy observations. 2. 45DEGREE ANGLE DESIGN: Engineered for comfortable and convenient viewing, the 45degree angle design enhances ergonomic observation, reduces neck strain, and provides a better viewing angle for celestial bodies and terrestrial objects. 3. 1.25INCH COMPATIBILITY: Designed for most refractor telescopes, these diagonal lenses fit standard 1.25inch eyepiece mounts, making them a versatile addition for both beginners and advanced astronomers seeking visual enhancement. 4. STURDY CONSTRUCTION WITH DUST COVER: Built with durable materials and a protective dust cover, this diagonal mirror maintains optical performance by preventing dirt and scratches, ensuring longlasting durability for extended telescope use.