Product Name： Headset microphone 
Item No.： HM-28S 

HM Series headset microphone is ideally suited for vocal sound and speech         
application which  requires much freedom of movement.          
Especially the smallest 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.         

Direct connection Type(D  series)         HM-28S1/2/3/4/5/6     
L1   Standard 2.5mm single  plug            
L2   Standard 3.5mm stereo plug        
L3   Special thread  type 3.5mm plug        
L4   Sennheiser type 3.5mm stereo plug        
L5   AKG type 3-pin mini XLR        
L6   Shure type 4-pin XLR        
L7   Audio-technica  type 4-pin  mini XLR        
L8   Special usb plug         

HM-28S1/2/3/4/5/6    
Element:Back Electret Condenser         
Polar Pattern:Omni/Omni/Omni/Uni/Uni/Uni-directional        
Frequency Response:20Hz- 20KHz /20Hz- 20KHz /20Hz-20KHz   
                                                50Hz- 16KHz /50Hz- 16KHz /50Hz-16KHz       
Sensitivity:-44dB± 3dB /-44dB± 3dB /-46dB± 3dB       
Output Impedance:1.8K/2K/2K/1K/1K/1KΩ± 30%         
Max.Input SPL:130dB         
S/N Ratio::>70dB         
Power Supply:1.5V-10V         
Cable:Φ1.5*1.2M         
Dimension::Φ3.5/Φ5 /Φ5/Φ7/Φ7/Φ7mm        
Color:Black, Skin or other         
Accessories:Windscreen