Fully Mobile: Use at Home or on the Go with GPS Tracking and 'Find-Me' Function Two-Way Communication, Automatic Fall Detection, Add Up To Three Nominated Contacts, One-Touch SOS Button, No Landline Needed Geo-fence Alerts – Defines a geographical area such that each time a user goes in or out of that area an alert will be sent. Battery Life 4-7days with low battery alerts
eBay