Control and communicate with up to 4 RS232 serial devices through your laptop ExpressCard slot. The StarTech.com EC4S952 4-Port ExpressCard-based Serial Card lets you add four RS232 serial ports to your laptop or ExpressCard equipped desktop computer, using an available ExpressCard slot. The ExpressCard Serial adapter is designed based on a single-chip architecture (as opposed to cards that use a "bridge chip"), providing native PCI Express communication for greater performance and reliability, as well as reduced power consumption and CPU load reduction of up to 48%. Compatible with ExpressCard 34mm and ExpressCard 54mm card slots, the 4 Port Serial ExpressCard includes a slot spacer for greater stability while installed in 54mm slots. Backed by a StarTech.com 1 year warranty and free lifetime technical support.