[Practical Use] Ideal 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 button to get prompt and thoughtful care, it can also be used as a doorbell. Widely used in homes, hospitals, communities, restaurants, offices, etc. [Easy to Use] Plug the receiver into the power outlet where you need to be reminded, the waterproof transmitter can be worn as a pendant or placed by the bedside. The receiver powered by 90~250V mains operates with a low power consumption transmitter that has a long standby time. [52 Alarm Options and 80m Range] 52 alarm sounds to choose from, with flashing LED alarm. The volume is adjustable on 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 will reduce the range), no interference with other devices. [Call Mode] Press the SOS button once (1-2 seconds), the receiver alarms once. If you need continuous alarm, press the SOS button several times. [Low Battery Indication] 1, if no action but the transmitter's LED light indicator continues to flash, it means the battery is low, replace the batteries; 2, The connection between transmitter and receiver may be lost after the battery has been replaced, 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.