Powered by the high performance SiRF Star III GPS Chipset - Fast GPS signal acquisition - Perfect for hikers and cross-country skiers to call for rescues when needed - Great to install in cars/vehicles safe-guard against auto-thefts . - Supports on-demand GPS tracking or continuous GPS tracking (remotely configured via SMS/Text Messaging) - In on-demand tracking mode GPS turns on only when tracking information is requested via SMS (thus saving power) - Built-in security features allows tracking requests from only authorized cell phones - Built-in quick dial and SOS buttons can instantly send current location (GPS coordinates) to designated receivers via SMS - Built-in rechargeable lithium battery (AC and Car Charger Included) - Support "geo-fencing" -- when person leaves preset geological area SMS will automatically be sent to designated receivers * Warranty information is located in the specifications section