... .Clear Voice 4.Volume control Colorful mobile phone retro style handsets for iphone Volume control button, LED light indication, answering/hanging up ... , Red, purple, yellow, pink, green, orange, black, whiter, pearly white3. OEM&ODM provided4. Frequency:20-20000Hz 5. Sensitivity: 111dB±3% 6 ... . DC plug: 2.5mm or 3.5mm DC plug optional for different Mobile phone. b. Answer Button: answering or hang up ...