Putting a call on conference may seem to be simple. But there is lots to it and features offered on Conference call ing by Zip is just impeccable. Some of the features of conference calling are mute & unmute, roll call, recording, holding a call and so on. Zip's calling device is now most sought after one by the corporates and the rates are too cheap. Putting a call on conference for just 2.4 Cents per minute is unbelievable.