This 7 segmentLED Displayhas 4 digits which are controlled byTM1637 Driver Chip. It requires only two connections to control thisTM1637 4 Bits Digital Tube LED Display Module.Also thanks to the I2CBus you can control it using only 2 wires, leaving more pins available on yourMicrocontrollerto connect other things. The module is a 12-foot clock with four common anode tube (0.36 inch) display module for driver IC TM1637, only two signal lines can make the MCU control four 7-segment digital tubes. There are several modules using thisTM1637 chip to form a 4 digit numerical display module.TM1637 has also keyboard input capability but is not used in this module. Pinout Description : GND GNDVcc 5VDIO D2CLK D3 Features : Ease to use. Ease of multiplexing. Can use as a 4 digit display unit. Can use as a clock display. DIY clock project. 4 digit display unit. Electrical/Electronic projects. The counter project using 7 segment display. 4 M2 screws positioning holes for easy installation