... LCD display, hand-free function, high sound quality. Key Features1.USB Interface PnP. No external power/sound card required2.High quality ... DTMF dialing, rings on an incoming callSpecifications1.Physical Connectors One USB Port2.Keypad DTMF keys 0~9, #,*,4 soft defined ... ~40 degreeSystem Requirements1.Pentium MMX 300MHz or above, with USB Interface, minimum 128MB RAM or more 2.Broadband or 56Kbps ...