HM Series headset microphone is ideally suited for vocal sound and speech application which  requires much freedom of movement.
      Especially the smaller size (the smallest capsule diameter of just 3.0mm)and lightest weight are ideal for application requiring minimum  visibility. Such as dance and sports instructors;Great for video use , this mini microphone is practically invisible.
     L1: Standard 3.5mm single(double) plug
     L2: SENNHEISER type 3.5mm stereo plug
     L3: Special thread type 3.5 single plug
     P3: AKG type 3pin mini XLR(3p)or other
     P4: SHURE type 4pin mini XLR(4p)or other
HM-42S-1/2/3/4
Element……………………Back Electret Condenser
Polar Pattern………………Omni/Omni/Uni/Uni-directional
Frequency Response……20Hz- 20KHz/20Hz- 20KHz/50Hz- 16KHz/50Hz- 16KHz 
Sensitivity………………-42dB/-46dB/-53dB/-45dB± 3dB
Output Impedance……..2200Ω± 30%
Max.Input SPL…………130dB
S/N Ratio………………>70dB
Power Supply……………1.5V-10V
Cable…………………………Φ1.5*1.2M
Dimension……………………Φ3.5mm/Φ5mm/Φ5mm/Φ7mm
Color………………………Black, Skin or other
Accessories………………….Windscreen