Push to talk buttonPhone line poweredVandal resistant stainless steel faceplate with heavy-duty metal call buttonsNon-volatile E2 memory (no batteries required)Touch Tone or pulse dialingProgrammable to dial up to 5 numbers on busy or ring no answerRed off-hook LED indicatorHangs up on CPC silence busy signal return to dial tone time out or a Touch Tone commandProgrammable to auto-answer on incoming callsRemotely programmableExtended temperature range (-15F to 130F)Flush mountable using included plasti