VuPoint MT03 EZ Secure Proximity Computer Lock Active Distance 3.3-39 Feet USB 2.0 high speed. Backwards compatible System Requirements Windows XP (32-bit), Windows Vista (32-bit), Windows 7 (32/64-bit) Security 128 bit AES Encryption / Decryption Active Distance Adjustable switch:Short: 1-3m ( Apprx. 3.3-10 ft), Medium: 4-7m (Approx. 13-23 ft), Long: 8-12m (Approx. 26-39 ft) Accessories Strap and USB dongle