The Wireless PC locking device is a USB gadget you attach to your computer. place the circular button in your pocket. When the system is on, if the button travels outside a 6 foot radius of your computer, the computer is not accessible until you return. This means if you have any reason to suspect tampering with your computer while you are not near it (read: dorm, co-workers, pets) fear no more. Just keep the green button in your pocket. $31. BUY