Features Specifications:Sell Wireless Surveillance Monitor/Baby Monitor/Car Monitor/Audio Monitoring/Surveillance  Super-sensitive audio surveillance. Much better quality  * Frequency: 900, 1800, 1900  * Embed four condense microphone  * 24 hour non-stop power supply  * All GSM SIM card compatible  * Microphone range(Meter): 5~7(Radius), 4 levels  * Receive sensitivity: -\+10K  * Working temp: -40~50'C  * Responding frequency: 1.2K~800Khz  * Stand-by time: 15 days Dimension: 2.4 x 1.5 x 0.8 Inc Operating Procedure( Caution)  Do not insert the SIM into the slot in the wrong direction.  * Charging up the device, Red and Green LED lights ON. When the device is fully charged up, only Red LED lights ON  * Place the SIM card into the slot with the contact points facing down (according to the pictures indication)  * The flash of red light indicates the SIM card is correctly inserted. SIM will completed initialization and maintain in stand-by status.  * Dial the SIM card number, you could hear the sound around the SIM card  * Please do not use it to engage any illegal activity