Practical & reliable Ideal as an alarm for those who need help quickly. like the elderly. the children. handicapped people. pregnant women or sick people. just press the call button to receive caring care. in due time and without shouting. It can also be used as a doorbell. Long range Up to 180 meters range in open area (walls and other objects will reduce the range). and the use of 16-bit encoding to eliminate interference from other devices allows it to work virtually anywhere in your home. More alert options Choice of 45 sounds (36 melody sounds and 9 alarm sounds) and three alert modes (Sound + Light. Sound only. light only). Sound volume adjustable on 3 levels. max. 110db ideal for older people. No power switch is designed to avoid forgetting to turn on. because it might miss an important emergency call (if not in use for a long time. remove the batteries to preserve their lifespan). Convenient placement transmitter The waterproof transmitter can be worn as a pendant or at the bedside. The receiver can be fixed to the wall. Pos freely on the desk or carry in the caregiver's pocket. Low battery indication 1. Without operation. but the device indication light keeps flashing or produces an abnormal sound. please replace the battery 2. the pairing between transmitter and receiver may lose contact after replacing the battery. the elements are not defective. just pair them manually to fix them. Receiver powered by 3 x AAA batteries (not included) Transmitter powered by 1 x button cell (included).