... functions while talking on the phoneSpecificationFunction button optional: Volume control, answering/hanging up button, LED light Frequency:20 ... key116DC: compatible with all mobile phones with slide volume control and answering/hanging up button116DI,116DB,116DN,116DS: ... Compatible with Iphone,Blackberry,Nokia,Samsung with Sidekey volume control and answering/hanging up button.116B: Wireless Bluetooth ...