Handheld mobile phone detectors utilize weak magnetic detection technology and radio wave detection technology. In non-contact inspections, they can trigger a red light alarm for mobile phones, Bluetooth headphones, and spy devices. They effectively exclude items like keys, coins, lighters, eyeglass frames, cans, pens, and stainless steel cups from triggering an alarm, thereby minimizing the need for manual security checks. These mobile phone detectors are made entirely of high-quality components, featuring simple operation, a lightweight and elegant design, clear and loud sound, and the function of automatic switching between power-on, detection, and alarm lights and sounds. They are particularly suitable for use in exam halls, leadership meetings, or any units with confidentiality requirements.