1.The measurement category is comprehensive and intuitive and has high precision. 2.This business card size, easy to carry and use dexterity. Name:special micrometer calibration ruler for microscope Thickness:0.10mm Measurement range: 100-1000 Micrometres in diameter line width 0.03mm-0.2mm : Mechanical/electronic industry ratio to component size, position deviation. Inspection of foreign bodies and scratches on the surface of electronic products. The the surface wire, the printing position and the size of the electronic product are inspected Type:B:Pure English Calibration Ruler Colour:Transparent Material:plastic Size:75X45mm Package Contents: 1 * Microscope correction ruler Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.