Practical & ReliableIdeal as an alarm for those who need quickly help, like the elderly, child, handicapped, pregnant women or sick, since nanny of caregiver can not always stay with patients or the disabled, simply press the call button to get timely and considerate care without yelling. It can also be used as doorbell. Long RangeUp to 80 meters range in open area (walls and other objects will reduce the range), and using 16-bit encoding to eliminate interference from other devices, provides the performance to work virtually anywhere in your home. More Alert Options38 alarm sounds to choose from, and sound + light alert ways.4 level adjustable sound volume (including mute), max 95db.Great for the aged.The receiver designed with LED torch, convenient for emergency usage. Convenient PlacementThe waterproof transmitter comes with hanging rope can be worn as a pendant, or placed at bedside.Receiver can be wall mounted with hanging rope, placed on the desk or carried in caregiver's pocket.Transmitter has waterproof ring, IP54 waterproof which is more durable. Low Battery Indication1, If no operation or press the transmitter, the receiver makes the special Ding, Ding, Ding sound (three times sound), this means the receiver has low battery, please charge the receiver in time. 2, The paring between transmitter and receiver may lose contact after very low battery, items is not defective, just pair them manually to fix. Receiver can be charged by USB cable transmitter powered by 1 x button cell (not included).