This USB to 4-Port Serial Adapter provides an external plug-and-play solution to add up to four RS-232 serial devices to a USB-enabled computer. Many newer computers, particularly laptop computers and handheld devices, no longer include the legacy serial ports, and desktop computers have reduced the number of serial ports supported. Users with serial devices may find themselves unable to communicate with installed equipment. The USB to 4-Port Serial Adapter is a great solution for connecting those legacy devices to a new computer. The four DB-9 serial ports ensure you'll have the connections you need, when you need them.