Check the listing for details. Transparency SEC Size Estimation Chart 17cm Covered Diameter Area Line Width. Condition: New. Listed at 13.21 USD. The SEC size estimation chart is made of PET clear plastic, which is resistant and unbreakable. This film transparent ruler is very thin, as thin as paper, and much thinner than ordinary rulers.Transparent film SEC pattern used for quality inspection and defect size estimation, with high accuracy, excellent transparency, minimal error caused by temperature, and long-term use. In addition, it has a protective film on the surface, which is waterproof and scratch-resistant to avoid inaccurate scales.The high-precision film ruler is perfect for factories, research institutes, measuring rooms and workshops. It can be used to measure the area of a wide variety of products, accurately detect and calibrate various measuring instruments, measure the reduction rate of photo printing films and detect the size of optical projection maps, etc.