1. Built-in white plate parameters. No need to calibrate each time which realize rapid measurement. 2. Double Locating: Illuminating locating and precise cross locating. 3. Switchable Double Measurement End Face: Large stable end face and small concave-convex end face. 4. Integrating Sphere Optical Path Design: Eliminating the stray light of main optical path and auxiliary optical path. Possessing the highest measurement stability and precision. 5. 4mm Measuring Aperture., Manufacturer: SOYWIM