optometry phoropter: 1.main machine + keyboard, digital operation 2.professional quality CE 3.favorable price, fast delivery digital optometry phoropter, auto phoropter #ZD3000: Specification:Sphere: 0.0 to -29.50 Diopters, step: 0.12,0.25,0.50,1,3 0.00 to +26.75 Diopters, step: 0.2,0.25,0.5,1,3Cylinder: 0.0 to ± 8.75 Diopters, step:0.25,0.5,1,3Cylinder Axis: 0°to 180°, step:1°,5°,15°Prism: -20 ...