... Button & LED Light Retro Handset for Iphone Specification1. Function button: Volume control, answering/hanging up button, LED light2. Frequency:20-20000Hz ... latest AXAET designed handset.2. Add new function--With the volume control function3. Improved call comfort4. Allows access to phone functions ... ,laptops,MID with 3.5mm plug hot-selling handset with volume control, answering/hanging up button