1. Microphone: digital silicon mark
2. Input voltage: 5V
3. Microphone battery: 60MAH
4. Charging compartment battery: 300MAH
5. Signal-to-noise ratio: 64DBM 3-step noise reduction
6. Transmission delay: 30MS
7. Sensitivity: -42DB
8. Frequency response range: 20-20KHZ
9. Transmission distance: barrier-free 20m-30m
