1. Input terminals: DCФ3.5DC Plug 4 
2. Working voltage: 3.7V 
3. Maximum output power: 90MW 
4. Noise level :18db 
5. Signal to noise ratio (SNR): ≥ 90db 
6. Power supply: 600mA  lithium battery 
7. Rated operating time:≥28h 
8. Noise Reduction Type: One-way feedback
9. Speaker diameter: Ф40mm 
10. Speaker Impedance: 32Ω 
11. Speaker frequency response: 20Hz - 20KHz 
12. Speaker sensitivity: 115dB 
13. Wire length: pvc wire, 1.2m