About:

The F-999B is a highly sensitive partition audio monitor for listening to audio on the other side of walls. It can be used with recording devices to record any audio picked up by the device. It is easy to use and appropriate for consumers and professionals.

• Electric current exhaust: 10mA
• Battery type: 3.7v lithium battery
• Working time: continue monitoring up to 100 hours
• Four audio channel: 1200Hz, 800Hz, 200Hz and Partition bougie monitoring
• Sound Sensitivty: -70db
• Maxmum audio amplification: 20000 times
• Able to penetrate: cement wall, steel wall, wooden wall, iron wall, glass and brick
• Receiver method: earpieces (included), recording by other audio device and FM transmit to other device.