There is a built-in serial input / output common cathode display driver. Can be connected to the miniprocessor and 7-segment digital LED display von eight digits. Also can be connected to the bar graph or 64 independent LED. Includes Type B BCD encoder, multiple scanning circuit and segment driver. A static RAM (8 * 8) is used to store data. Multifunctional and practical. A comfortable 4-wire interface can be connected to all general miniprocessor Only 3 IO interfaces will be used to drive a dot matrix display Material: PCB Operating voltage: 5V LED color: Red screw opening hole: 3mm cable length: 20cm item size: 12.8 * 3.2 * 1.5 cm / 5 * 1.3 * 0.6in item -Weight: 51g / 1.8 oz package list: 1 * ules; 1 * Cable Note: Random color, don't accept the specified color. Note: Light shooting 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.