Feature:Super mini size, easy to carry and hide.Very easy to use: just call the SIM number installed in the device. In just a few seconds you will hear a voice within a 10-meter radius.GSM Quad Band (850/900/1800, 1900Mhz) can work perfectly worldwide.Built-in 2-microphone to ensure good sound quality, outstanding sound quality makes spy more reliable.Supports preset number, phone number and mobile number, both are fine.Element type: Two-way audio deviceAcoustic alarm function is available.Long standby time: built-in 200mA buffer battery, with activated acoustic alarm function, it can last 3-5 days; It may take about 12-15 days if the acoustic alarm is deactivated.Materials: Molded plasticDimensions: 4.3 x 3.2 x 1.4 (cm)Power: Built-in 200mAh lithium-ion batteryColor: BlackVoice control on: 3-5 daysMain Function: Tri-Band GSM Two Way Audio Spying DeviceVoice control from: 12-15 daysWorking hours: 5 hoursMicrophone range: 5-7 meters radiusInclude package:1x bidirectional audio device1x USB cable1x User Guide (Chinese and English)Note:Color deviation may vary due to different monitor settings"