Convenient Use: Ideal as an alarm for those who need help quickly, such as the elderly, children, disabled individuals, pregnant women, or sick patients. Simply press the button to call for assistance and prompt care. It can also be used at the door. Widely used in homes, hospitals, communities, restaurants, offices, etc. Easy to Use: Plug the receiver into a power outlet where you want to be alerted. The waterproof transmitter can be worn as a pendant or placed by the bedside. The 90~250V-powered main receiver works with a low-power transmitter that has a long standby time. 52 Alert Options & 80m Range: Choose from 52 alarm sounds, with a flashing LED light. 4-level adjustable volume, 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 from other devices. 2 Alarm Modes: Call mode: press the SOS button once (1-2 seconds), the receiver will sound an alarm. Emergency mode: hold down the SOS button for 3 seconds or more, the receiver will alarm continuously until you press the volume button on the receiver. Low Battery Indication: 1. If there is no function but the LED light on the transmitter continues to flash, it means the battery is low, please replace the batteries; 2. The pairing between the transmitter and receiver may lose contact after replacing the battery. The items are not faulty, just pair them manually to fix.