Product Features: USB to RS232 converters/cables/dongles Single-chip upgrade solution for Legacy RS232 devices to USB interface USB Barcode/Smart Card Readers Healthcare/Medical USB Interface Data Transfer Cable Personal Infotainment/Media Player Docking USB Interface Cellular/PDA USB Interface Data Transfer Cable Serial-over-IP Wireless Solution USB Modem/Wireless/Zigbee USB Interface GPS/Navigation USB Interface Point-of-Sale (POS) Terminals/Printers PC Docking Station/Port Replicators Industrial/Instrumentation/Automation Control USB Interface MCU-based devices to USB interface Set-Top Box (STB) / Home Gateway USB Interface BatteryCharger Application This product is designed for laboratory, product testing, low-cost MCU communications and other applications. There are four wires: Red +5 V Black GND White RXD Green TXD Package Included: 2pcs PL2303TA USB to TTL Serial Cables