Refractor telescope aperture 70 mm focal length 350 mm focal ratio 15 optical systems fraunhofer achromatic refractor suitable for beginners max useful magnification 140 x tracking altazimuth tripod aluminium tripod features goto telescope feature easily transportable minimum useful magnification 10 resolution power 164 bogensekunden light collecting power 7mm pupil 100 border size 11 mag eye piece 125 eyepiece focal length in mm 10 20