Nautical Compass Telescope - with built-in distance measuring scale and orientation compass, and you can calculate the object distance, by reading the data scale directly from the left eyepiece scale , built with the illuminated directional compass bearing calculation (adapted by dark illumination button to illuminate the inside of the ruler and compass)Professional and coated optical glass - 50mm large lens, 26mm large eyepiece, BAK4 system FMC optical lens green film pure anti-reflective coating lens, FMC blue coating eyepiece, which can significantly reduce the reflection of light, after being entered the lens, which effectively improves light permeability, image brightness and sharpness in low-light conditions, its performance is also very good;Binocular focusing system - level focusable binoculars, which meet your different vision needs of right and left eyes 100%,, eyepiece cover design quickly folded, allows you to take eyeglasses at use; the green rubber skin, the appearance of uneven lines, which can easily get your hands holding binoculars firmly stable