the computer automatically enters “Lock Mode” when the user is away from the computer by more than the effective range. The computer automatically resumes normal operation when the user is back to within an effective range. Once the computer enters the “Lock Mode” a password is required to use the computer if the transmitter / receiver pair is not available to unlock the computer. One unique security code in the transmitter computer automatically recognizes the code itself. Software driver: support for MS WIN98 SE, ME, XP, 2000 and higher. One transmitter can be shared with multiple computers. One transmitter can be shared with multiple computers. Operation frequencies 315 MHz / FCC. Transmitter Power Supply: DC 3V; Battery usage: approximately 2000 hours.