USB-COM-SI-M adds one industrial RS-232 serial port with optical isolation. This item does not require external power fully supports a simple USB port (USB 1.1 / 2.0 /3.0) 2000V DC optical isolation/25KV ESD surge protection Industrial metal housing with built-in surface mounting flanges (DIN rail compatible with DIN-RAIL-CLIP, sold separately) Full RS-232 modem control signals and hardware/software flow control OS Compatibility: Windows 98, Me, XP, 2000, 2003, CE, Vista, Windows 7, and Windows 8 as well as Linux and Mac OS 10.X