... .50 Diopters, step: 0.25,0.50,1,3 0.00 to +26.75 Diopters,step: 0.25,0.50,1,3 Cylinder: 0 ... .0 to ± 8.75 Diopters,step:0.25 Prism form ... .37D ,±0.50D PD: 48 to 80mm in 0.5mm step Retinoscope: +2.00D or+1.50 both sides Corneal alignment ... : 12 to 20mm by 2mm step and 13.75mm Field of view: 35° Power source: AC110 ...