This top shelf wireless bug detector can trace multiple digital transmissions including GSM, Bluetooth, cellular and GPS. While the sensitivity of lower-grade RF detectors is spread along a wide frequency range, those units often have trouble detecting weaker signals such as Bluetooth, Wi-Fi and Wi-Max.Each signal type has a dedicated bar graph on this unit to show the corresponding signal strength. There is also an attenuator button to use when honing in on a specific signal! When the unit is in “display mode” the signal type will be displayed in the ‘Extra Data’ display screen.The Multi-Unit Wireless Detector also has audible, silent, visual, and vibration modes. Detection range is approximately 30 feet.