Add two RS-232 ports to your desktop: This USB to Serial Adapter lets you add two RS-232 ports to a desktop system equipped with a USB motherboard header; the USB adapter supports Com port retention Use inside the PC case: Unlike other USB , this USB to serial adapter cable is designed for Use inside the PC case, creating an entirely internal solution with no extra adapters needed Bus powered: No separate power supply or battery is required High data throughput: The two-port internal USB to serial converter provides a single-chip USB to asynchronous serial data transfer interface; FIFO receive and transmit provide high data throughput The USB serial adapter offers a cost-effective solution that bridges the compatibility gap between modern computers and legacy serial peripherals; USB 2.0 full speed compatible