Generic Nuoya001 New Mini Hidden Spy Earphone Wireless Earpiece Headset Microphone Detection 100% Brand New, ship from China, we ship by China Post Air Mail service, 9-15 days to arrive. How to use: 1.Open battery door, install the battery perfectly and push battery door into battery box gently. Put the earpiece into ear canal by holding the handle and the slight sound of current indicate working order. 2.Adjust the volume of drive equipment to reach satisfaction. 3.Set mobile phone to automatic return or vibration. 4.Put the inductive loop around your neck and connect the inductive loop to the drive equipments (mobile phone, radio) which are attached to or beneath users clothing. One transmits message with radio, the other wearing an earpiece and inductive loop who also has a radio can hear the message very clear. Because the inductive loop inducts the message from the radio to earpiece and then earpiece transforms the electromagnetic inductive signal to audio signal to reach the wireless inception. Communication distances and radio power are the direct proportion. You can communicate with others freely once network exist when you use mobile phone Package Content: 1x Earpiece 1x Loopset 1x Battery - 337 SR416SW 1x Inverter from 2.5mm to 3.5mm Mini wireless earpiece is a micro-mini wireless inductive receiver which transforms audio signal through electromagnetic induction. These products make the covert communication possible when it is inconvenient to expose earpieces. earpiece is widely used in many departments .Using this device;You can hear the voice from the person other side,and the person of the other side can also hear your vioce. Features and Highlights