Refractor telescope aperture 127 mm focal length 952 mm focal ratio 175 optical systems ed apochromatic refractor max useful magnification 254 x tracking without ota mount without ota tripod not included minimum useful magnification 18 coating enhanced multilayer desposition emd finderscope 8x50 eye piece 2 crayford 110 eyepiece focal length in mm 2 mm included in delivery aluminium case