“What makes SkyAngel911FD different?” SkyAngel911FD has no monthly service fees of any kind. Once you buy the device you will never pay to use it. SkyAngel911FD is similar to an “OnStar" for Emergency Situations. This premier alert system provides freedom with security. With the touch of a button, you can talk with 911, anytime, from virtually anywhere there is cell service. Other products like a traditional Personal Emergency Response System (PERS) only allow you to call for help within 150 to 600 feet away of a base station. Unlike a PERS, SkyAngel911FD works both indoors and outdoors to ensure anyone has peace of mind knowing that help is always available. SkyAngel911FD will use any available cell tower so you don't have to worry about coverage. (Cell coverage is not available in all areas - this works similar to a cell phone). If all lights go off after charging, device is in sleep mode and still functional. Press any button to wake it up..device will automatically wake up if activated by pressing SOS or if it detects a fall.