ITEM NAME:4 Bits Digital Tube LED Display Module With Clock Display TM1637 for Arduin BX Features: Data link: https://www.mediafire.com/file/0rpuccsc00e20rc/144_LED_Display_Module.rar/file Display common anode for the four red LED Digital tube 8 gray adjustable Level control interface for 5V or 3.3V 4 M2 screws positioning holes for easy installation Size:42X24X12mm Interface 4 digital display module: (the last picture show) Control Interface : A total of four pins (GND, VCC, DIO, CLK), GND to ground , VCC is the power supply , DIO of data input and output pin , CLK is the clock signal pin ; Digital tube: 4 common anode score points with 0.36 inches LED, red highlights ; Positioning holes : 4 M2 screws positioning hole diameter is 2.2mm, the positioning of the module is easy to install , to achieve inter- module combination. Package Includedï ¼Å¡ 1pc x  4 Bits LED Display Module.1pc x 4 Bits LED Display Module. Interface 4 digital display module: (the last picture show). Display common anode for the four red LED. Digital tube 8 gray adjustable.