The ATEN USB-to-Serial RS-422/485 Hub provides an external plug-and-play RS-422 / RS-485 serial connection for computers, notebooks, laptops, and handheld computing devices that support the USB specification. It provides a quick, simple, and cost-effective solution and is ideal for various communication and automation applications. ATEN provides 4 models in this series: 2/4-Port USB-to-Serial RS-422/485 Hub; 2/4-Port USB-to-Serial RS-232 Hub.