The Medi Alarm has a 50 metre radius in and around the home. It comes with a waterproof neck pendant and non waterproof wrist button. It is perfect for use around the home. The Medi alarm base unit simply works off a landline with the supplied adapter. It shares the normal home telephone line. Three telephone numbers (either mobile or landline) of friends / family can be entered into the base unit via the keypad. Pre-record your own message eg: ” This is Mum I need help” To operate, simply press the SOS button on either the pendant or wrist strap to start the Medi Alarm base unit dialing 3 nominated and entered telephone numbers of friends or family. The unit will keep dialing and be playing a pre-recorded ‘help message… until one of the people in your list answers the call for help. By pressing 55 on their telephone this will stop the sequence of calls, and if the wearer is in the same room as the machine it will become a two way conversation. As well Medi Alarm will repeat the sequence over and over again until one of the three nominated contacts take the call. Medi Alarm is NBN compatible. Please view our video for set up etc.