Noise reduction Hearing-Protect Light duty Ear Muff headset for walkie talkie two way radio

HP60 Hearing Protection Ear Muff

1 Earphone
Size                   Outer Diameter 50mm
Weight              14.8 gram
Magnet              Materials Ferrite Size Φ20.5*4.5mm
Impedance      300 Ω At around 1KHz
Power Rating     Normal 30mW RMS
                             Maximum 50mW
Output Sound Pressure Level
        83±3dB /100mW /1cm  
        With Artificial ear per channel
        Average at 1.0K, 1.2K, 1.5K, 2.0KHz
Resonance Fo    100Hz
Frequency Range 100Hz~3000Hz
Distortion      5% Maximum at 1KHz /100mW /1cm
Abnormal Sound Test
        Must be Normal Tested by        
        3.0Voltage Sine Wave
Load test
        30mW RMS  
        White noise for 48hrs

2  Microphone
Type          Noise Cancelling Dynamic Mic.
Case Material   ABS Plastic
Sensitivity
        0°-71dB±3dB (at L=50cm)      
        (0dB=1V/Pa,1KHz)
Impedance      Low impedance 150 ohm
Frequency      600Hz~12000Hz
Standard operation voltage  1V
Sensitivity reduction      Within -3dB at 1V
3.  Boom Type  Universal Flexible and Hinged Wire
4.  Plug             3.5mm jack
5.  NRR          Noise Reduction Rating: -23 dB
6.  Color      Black/Yellow/Others