The My Medical ID USB is a portable flash drive. It has 256 Megs of memory to store your latest medical information and contact list. Over 95% of emergency responders will check for a bracelet, necklace or key chain for medical information. The unit works in Windows based PC computers - Windows 98, Windows XP, Vista and more. Keep you medications and supplements updated - hand the unit to a Doctor, Nurse of Medic and they can view and print out the list easily.