SKYOPTIKST 1.25 inch high reflective dielectric film Star diagonal is made of aluminum alloy. The lens is a high-precision plane mirror with 1/10 wavelength error. The surface is coated with a dielectric film with a reflectivity of up to 99% to improve the performance of the mirror. The surface of the mirror tube has undergone black glossy oxidation, with a Chinese red side panel, which is aesthetically pleasing and of outstanding quality. The excellent quality of this flat reflector brings you more enjoyment when observing the sky, making your observation more convenient. The design of the eyepiece locking protection device ensures that the surface of the eyepiece is not damaged when the eyepiece is locked, and special treatment is carried out to eliminate stray light inside. In order to facilitate the observation of special celestial bodies by observers, this flat reflector is also designed with a filter interface for easy installation and unloading of filters.