1. Material: ABS 2. Built-in lithium battery 30mAh 3. Charging time: about 2 hours 4. Working voltage: d.c.3.7V 5. Working time: about 35 hours 6. Frequency range: 450-3400MHz 7. Input noise: less than or equal to 32dB 8. Working current: less than or equal to 1.2mA 9. Total harmonic distortion: less than or equal to 10% 10. Sound output: less than or equal to 129±3dB 11. Sound gain: greater than or equal to 40dB±5dB 12. Net weight: 6.5g
