Product Description: Upgraded K2-B Deluxe Electromagnetic Field Detector (with built-in normally on/normally 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 will emit a low-volume alarm when it detects electromagnetic fields. To avoid disturbing the investigation, the sound is very low. The low-volume alarm it emits is similar to a Geiger counter, and as each detector group turns on, the sound gradually increases (gets louder). But once again, it should be emphasized that the sound is very low to avoid disturbing the collection of evidence. All other KII specifications and operational functions are the same as other KII detectors. KII-B model: The KII-B adds a low-frequency buzzing sound to the popular KII electromagnetic field detector, which emits a warning sound when an electromagnetic field is detected. This audio feature allows paranormal investigators to simultaneously see the LED indicator light illuminate and hear the warning sound of electromagnetic field detection. Unlike the standard KII, the KII-B allows investigators and others to hear warning sounds for electromagnetic field detection. Unlike the standard KII, the KII-B allows researchers and others to directly hear changes in electromagnetic fields. This audio technology also helps to validate your experience, as some people typically use tape recorders or digital video recorders to record changes in electromagnetic fields. This is an excellent audio alarm function used to monitor electromagnetic field changes in remote areas. As the intensity of the electromagnetic field increases, the buzzing sound will also increase. Professionals, including TAPS (the supernatural investigation team in the science fiction TV series \"Ghostbusters\"), use these devices. If you want professionals to use high-quality electromagnetic field detectors, then this is what you need! Electromagnetic fields are generated by various types of electronic devices. Electromagnetic fields are everywhere, originating from household appliances, mobile phones, wiring, and even the human body. K-II electromagnetic field strength meters can measure electromagnetic fields, identify devices with high radiation, help users make informed choices, and reduce exposure to electromagnetic fields. Fluctuations in electromagnetic fields are also related to the occurrence of certain unknown phenomena, including so-called \"ghost sightings.\" K-II electromagnetic field strength meters can measure electromagnetic fields, identify devices with high radiation, help users make informed choices, and reduce exposure to electromagnetic fields. Fluctuations in electromagnetic fields are also related to the occurrence of certain unknown phenomena, including so-called \"ghost sightings.\" The K-II is powered by a 9V battery and has a measurement range of 5 milliGauss. Can instantly react to fluctuations and peaks in electromagnetic fields. Can detect extremely low frequency range (ELF) (50 to 1000 Hz) and extremely low frequency range (VLF). Easy to use, just open/close. Equipped with an easy-to-read multi-threaded LED display. At a frequency of 50-60Hz, the accuracy is 5%. Packing list: 1 K2 black model with battery included (color box)