Medical Alarm Device That Allows You to Speak and Listen Directly Through the Pendant two-way audio speaker, can speak and listen at the same time :Important NOTE : MUST BE USED Plain old telephone service (POTS), not VOIP nor commercial phone system. water-resistant, with water drainage port lights to indicate signal range and battery large and easy-to-find emergency button, use ground line, a secured way to ensure the receiver knows who you are No monthly fee, when you need help, call your family and if they are not available, call 911. --all by ONLY ONE BUTTON PUSH