Nortel Meridian M5316 Phone NT4X42 (Black/Refurbished)Handsfree operation permits you to engage in a conference call while simultaneously performing others tasks. During the conference call, use the Mute key to confer confidentially with another person in the room. Thirteen programmable line feature keys let you tailor your set to suit your needs. The Program key lets you further customize local features on your set, such as time and date. The M5316 gives you one button access to the MDC features you use