FeaturesPD Meter is a digital precision optical instrument used to measure distance betweenHuman pupils in the process of optometry. This device is designed in a scientific and reasonable way, integrating technologiesOn optics, microelectronics. The corner reflection light coincidence method is used. This operates by aligning luminous point on the pupils with measuring line. Results are displayed digitally. Measurements are given: Right, right+left, left. Results are accurate to within 0.25mm. Measurements can be made for a single eye or for both eyes. Possible to measure PD of focusing-point distances ranging from 30cm to infinity. Automatically switches OFF one minute after operation is completed, thusConserving power. Distances from tops of the corner to lenses or frames can also be measured. HS Code: 90185000 Trademark: FAR EAST Model NO.: PD-48 Productivity: 2000PCS/MONTH Unit Price/Payment: USD88.00/PC Origin: China Packing: Carton Min. Order: 6PCS Transportation: BY SEA OR AIR Company: Langfang Far East Prosperous Optical Instrument Co., Ltd.