[Convenient and reliable] It is very suitable for the elderly, children, the disabled, pregnant women or patients who need to Quick help, because the caregiver's nanny cannot always accompany the patient or the disabled, just press the phone button without shouting you can get timely and thoughtful care. It can also be used as a doorbell [Long distance] Open areas are up to 300 meters (walls and other objects will reduce the distance) and 16-bit encoding is used for eliminate interference from other devices, providing the performance required to work almost anywhere in the house [Easy to place] The waterproof transmitter comes with a lanyard, which can be worn as a pendant or placed on the head of the bed [How to use] The transmitter is equipped with a battery to be used, and it is placed by your side; the receiver needs to be plugged into a home socket