Tripp Lite's USB to serial adapter enables up to 4 serial devices (RS-232) to be connected to a computer through a single USB port. It is perfect for applications where there are insufficient or no serial ports available. Use it with serial devices such as touch screen monitors, digital cameras, card readers and printers. Each channel is capable of functioning at a 460.8 Mbps data transfer rate. Plug-and-play / hot-swappable allows you to add or remove a device at any time. Does not require any external power.