9mm focal length and 66 degree ultra wide angle provide an amazing magnification and broad vision,perfect for lunar observations,medium sized star clusters, especially for deep sky targets.Clear and crisp image: FMC(fully multied coating) green film can reduce the reflection and refraction of light and enhance the transmission of light；6 Lenses in 4 Groups:Multiple group lens combination to improve optical performance, and delivers sharp images with good color correction and contrast; --Blackened lens edges and internally blackened eyepiece barrel to avoid internal reflection and provide a crisp image. The SVBONY super 1.25" 40 mm plossl eyepiece engineered with 4 element design and offers a generous 40 degree apparent field of view. It is awesome for perusing the sky and finding things like constellations, clusters, and galaxies in the field of view. The SVBONY fully metal 1.25" Mirrors Diagonal zenith mirror offers an upright figure which is but turned backward in left and right position. The mirror is compatible with refractors, Celestron EQ, Meade Infinity and similar telescopes. It is not suitable due to the length reflectors for Newton. Brass Compression Ring, provides a uniform pressure receiving area when holding the eyepiece; screw clamps effortless fixes more firmly and will not damage your eyepieces