This ExpressCard to PCMCIA Laptop Adapter Card converts a laptop ExpressCard port into a PCMCIA CardBus port, allowing you to use older CardBus cards with a newer (ExpressCard capable) laptop computer. Ideal for use with Ethernet LAN, Broadband, Modem, and other CardBus expansion cards, the adapter eliminates the expense of having to replace your existing CardBus cards for the sake of compatibility. The adapter card supports common operating systems including Windows XP, Vista, and Mac OS X and up.