Description: brand new and high quality Feature: Plastic PD meter/PD Ruler, durable, firm and has a long service life. Anti-slip handle, easy and simple to operate. It is designed to measure the pupil distance. It is a very good promotional item and perfect for hospital, pharmaceutical supplies. PD Ruler only, other accessories demo in the picture is not included! Specifications: Item Type: PD Ruler Material: plastic Size: 21x5x0.7cm/8.2x1.9x0.2in Color: White Quantity: 1 PC Notes on measuring interpupillary distance: 1.Look straight ahead with your eyes, and keep your eyes on a still life about 20 meters away (if you are in a house, look into the distance). Do not turn your eyes during the measurement. 2.Do not measure yourself in the mirror, please ask your family or friends to help you measure. 3.Please start from the "0" degree scale of the ruler, do not start from the edge of the ruler. 4.Measure multiple times and take the same value (to mm, for example: 64 mm). Note: Transition: 1cm=10mm=0.39inch Please allow 0-1cm error due to manual measurement. pls make sure you do not mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you! Package Includes: 1 x PD Ruler