Refractor telescope aperture 50 mm focal length 600 mm focal ratio 112 optical systems fraunhofer achromatic refractor suitable for children max useful magnification 150 x tracking altazimuth mount altazimuth az 1 tripod aluminium tripod telescope feature easily transportable astrophotography function none minimum useful magnification 7 coating fully coated series national geographic astronomy finderscope 5x24 eyepiece type huygens eyepiece