Feature: 1. FUNCTION: Expanding a single USB to 4 UART serial ports, this serial port module can achieve simultaneous communication. 2. 4 WAY TTL PORT: All the 4 serial ports are using XH2.54 port, and the 4 way UART all have TX or RX indicator to show statue. 3. EASY SWITCHING: VCC, TX and RX can switch among 5V, 3.3V, 2.5V and 1.8V, and the switching is very quick and easy as well. 4. WIDE APPLICATION: Allows for flexible application on electronic equipments and automation equipments, powerful and useful. 5. GOOD WORKMANSHIP: Adopting excellent workmanship, the serial port module is not prone to cold joints, simple to install. Specification: Item Type: Serial Port Module Material: Printed Circuit Board Working Voltage: DC 5V (USB power supply) Function: To achieve simultaneous communication with a single USB to expand 4 UART serial ports. Applicable Scenarios: For electronic equipment, automation equipment. . Package List: 1 x Serial Port Module Note: Do not use the product in an electrostatic environment, otherwise static electricity will damage the electronic components.