- Highly sensitive metal detector, enables monitor the entire next door
- Monitors the voice on the other side of the wall through concrete, reinforcing steel bar, wood, metal, glass and brick
- With earphone jack and record voice output for recording simultaneously as the general recorder
- Four audio sections: section (200Hz), section (400Hz), section (800Hz), section (1,200Hz), adjustable according to the spot situation
- Highest frequency enlarged can be 50,000 times
Applied for business monitor and surveillance information collection
