The plate9m2p16 dual port serial plate adds two db9 serial ports to the rear panel of a computer connecting to two idc10 header connectors on the motherboard constructed of high quality components this durable dual port serial bracket is backed by startechcom39s lifetime warranty please refer to this product39s technical specifications to ensure compatibility with your motherboard save space by adding two db9 serial ports through a single expansion slot on the back of your pc backed by start