For use with your mobile phone for comfortable conversation. Corded handset plugs into standard 3.5mm headphone jack on cell phone. Use at the office, at home or on the go! Can be used anywhere—no batteries required. Simply plug in the handset and instantly use your cell phone just like a retro phone. When the phone rings, just answer and talk using the retro, coiled wire handset. Cord reaches up to five feet. Handset includes basic functions such as volume control, flash, answer/hang up button.