HiLetgo 2pcs 4 Bits Digital Tube LED Segment Display Module With Clock Display Red Common Anode For Arduino UNO R3 4 M2 screw holes for easy installation. 4-digit LED display module with LED brightness adjustable and clock point. Display device is a total of 4 red LED word tube. Digital tube 8 grayscale adjustable. The driver IC is TM1637, only two signal lines can make MCU control four Digit 8-segment LED. Can be used to display decimal, letters and so on. Control interface: a total of 4 pins (GND, VCC, DIO, CLK), GND to ground, VCC for the power supply, DIO for the data input and output pins, CLK for the clock signal pin. You can return this item for any reason and get a full refund: no shipping charges. The item must be returned in new and unused condition. Go to Your Orders to start the return Print the return shipping label Ship it!