This device is designed in a scientific and reasonable way, integrating technologies on optics, microelectronics.

Specification:

• Range of data display: Binocular pupillary distance: 44～83mm
  Left or right pupillary distance: 22～41.5mm
• Effective range of measurement: Binocular pupillary distance: 45～82mm
  Left or right pupillary distance：22.5～41mm
• Indication error: ≤0.5mm
• Rounding error: ≤0.5mm
• Distance of target: 30cm～∞
• Power source: Voltage：DC 6V
• Specification: 5# AA battery, Quantity：4 pieces
• Time for automatic shut-off: 1 and a half minutes after stopping operation
• Size: 219d × 169w × 86h mm
• Weight: 0.7kg

• PayPal is the best.
• Bank transfer is also ok but it's not recommended because it will take much longer.

• We will offer combined shipping cost for multi-item purchase, please email to ask.
• We shipped the package out within 4 days after payment received except weekend&holidays.
• Insurance are not included in the postage, none package lost case till now, please email us if you want to buy insurance.
• We ship all the goods by EMS (Express Mail Service).Package can be tracked online.
• It will take about 10-14 days to arrive US, Australia and most European countries.
• Shipping is free for US. Australia and West European Countries, if you are located in other countries please email us for freight confirmation before bidding.

• Return is acceptable in 7 days of receipt and please remember to contact us before arrange the return, DO NOT send item to the address on the package, we won't get it and you will not be refunded.
• Return item must be in original conditions, include package.
• A 25% re-handling fee will be charged according to seller's inspection.
• For defective or wrong items, we will offer full refund, for any other reason.
• Shipping and handling charges are not refundable.