M89B LED Light Source Hardware Glasses Test Tool Suitable For Glasses Blue Light Blocking Lenses Environmental Protection MaterialsOOTDTY Features: The color change of the lens changes a few seconds after you put it into the test area. Press the blue light blocking lenses on the blue light test card part and insert it into the test area. The color of the unobstructed part of the blue light test card becomes darker.15 led purple light, arc-shaped, wider detection range. The lens tester is equipped with 15 LEDs, low heat, low power consumption, energy saving and environmental protection. It is used to test whether the glasses/lenses block blue light or change color. Specification: Material: ABSyp: European Standard Plug/UK Standard PlugSize: 21x12x 8cm/8.26x4.72x3.14inchesPackage Included: 1 Set of Color Changing Lens TesterNote: Please allow 0-1cm error due to manual measurement. Pls make sure you don't mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you!