Improved call comfort
Allows access to phone functions when making calls
Eliminates over 99% of absorbed phone radiation
Turns your tablet computer into a telephone via Skype or VOIP applications
Noise reduction system
Pick up/hang up button (may not compatible with some phone)
Volume +/- button (for Item 2: only apply for iPhone 4 & 4s/iPhone 3GS/iPhone 3G， iPad， iPod. For others phone， you may direct use your phone to control the volume)
Supplied with a 3.5mm plug
Receiver and microphone function

Frequency Respond: 20-20000Hz
Sensitivity: 111dB±3%
Impedance: 150ohm
Colour : Black，blue，pink.