Cell Ranger USB-Powered Cell Phone Signal Booster 2-3 bars extra signal for any cell phone or 3G data card More signal means better call quality for cell phones, and up to 100% faster download speeds for 3G data cards. Prevents dropped calls and improves call clarity No drivers or software needed  PORT only uses USB for power. Simply place antenna near a window (up to 15 feet away) and plug into you laptops USB port. Cell Rangers advanced circuitry does the rest.