⭕ This is a really nice Canon RK-F1 Fully Automated Auto Refracter and Keratometer with 3D alignment for the most accurate readings. It is in excellent shape and has had very little use. Unit is less than 3 years old, in perfect working order. 30 days return policy if not as described. Shipping or collection local. Advanced Full Auto technology for 3-D Auto alignment, auto tracking, auto measurement and auto print-out! Just press start!. Other features are peripheral keratometry, retro illumination and diameter measurement.