When hands-free (full duplex) communication is a must, TeamTalk™ allows users to communicate with each other live, without delay, and without having to press a button, just full-time talk/listen like a conference call. When hands-free communication is not needed, TeamTalk™ users may switch to "push-to-talk" mode and use a PTT button to transmit only when desired. The TeamTalk™ T-9 system simultaneously supports up to 9 full-duplex users "live" plus an unlimited number of additional users in PTT mode.