Practical useIdeal for use as an alarm for those who need help quickly, such as the elderly, children, disabled, pregnant women or patients, sick, just press the call button for quick and considerate care, it can also used as a doorbell. Widely used in home, hospital, community, restaurant, office, etc. Easy to use Connect the receiver to power where you need to remind yourself that the waterproof transmitter can be worn as a pendant or placed by the bed . The 90~250V mains-powered receiver works with a low-power transmitter that has long standby time. 52 warning options and 80m range 52 warning sounds to choose from, with flashing LED warning. Volume adjustable in 4 levels, max 110db ideal for the elderly. No power switch is designed to avoid missing the important emergency alarm. Up to 80 meters range in open area (walls and other objects reduce the range), no interference with other devices. Call Mode Press the SOS button once (1-2 seconds), the receiver will alert a time. If you need a continuous alarm, press the SOS button several times. Low battery indicator1, if no function but the transmitter LED light keeps flashing, it means the battery is low, please replace the batteries; 2, The connection between transmitter and receiver may be lost after replacing the battery, pair them manually to repair them; 3, Use a flat screwdriver (not included) to pry open the side of the transmitter to replace the battery. Welcome to our GeekAtmosphere store!