[Convenient and reliable]It is very suitable for the elderly, children, the disabled, pregnant women or patients who need quick help. The caregiver's nanny cannot always accompany the patient or the disabled, so they can just press the phone button without shouting and get timely and thoughtful care. It can also be used as a doorbell. [Long distance]Open areas are up to 400 meters (walls and other objects will reduce the distance) and 16-bit encoding is used to 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. The receiver can be hung on the wall with a cord, placed on the table or in the caregiver's pocket. A: 1 * receiving hosts and 1 * transmitte B: 2 * receiving hosts and 1 * transmitter C: 1 * receiving hosts and 2 * transmitteNotice: 1. The monitors used are different, the computers are different, and the camera angles are different, there may be problems with the angle and color. 2. Purely manual measurement, there may be 0-1cm error.