Smart Lab FEC-001 Smart EM Checker EMF detector For Smartphone of Android, Apple IOS (Without Key Holder) Detect and Counter "Electromagnetic Wave" by Semiconductor sensor. Smartphone App "Smart EM Checker" in Android Play Store or Apple App Store. Real-time display of measurement results using Smartphone App "Smart EM Checker" Ultra Compact Design & Ultra Low Power use 3.5 earphone jack of a smartphone