Product Description: Upgraded K2-B Deluxe Electromagnetic Field Detector (with built-in normal on/off switch), low volume warning sound, with included instructions - has the same efficiency and power as the original K2 detector. These models have been used in hundreds (or even thousands) of investigations and have achieved excellent results. Please note: This KII detector emits a low volume warning sound when it detects electromagnetic fields. The voice is low to avoid disturbing the investigation. KII-B model: KII-B adds a low-frequency beep sound to the popular KII electromagnetic field detector, which emits a warning sound. Unlike the standard KII, the KII-B allows investigators and others to hear changes in electromagnetic fields on their own. This audio technology also helps electromagnetic fields. Professionals, including TAPS (the paranormal investigation team featured in the sci-fi TV series \"Ghostbusters\"), use these devices. need! Electromagnetic fields are generated by various types of electromagnetic devices. fields, identify devices with high radiation, help users make informed decisions, and reduce exposure to electromagnetic fields. so-called \"ghost sightings\". The K-II is powered by a 9V battery and has a measuring range of 5 milliGauss. and very low frequency range (VLF) (1000 to 20000 Hz). Easy to use, just turn on/off. Equipped with an easy-to-read multi-page LED display. The accuracy is 5% at a frequency of 50-60 Hz. Packing list: 1 K2 black battery-free model (color box)