What's the name of something that rings when someone comes in? My friend went back to her hometown to live alone, and someone pulled her door in the middle of the night, and she

Greeter, also known as electronic induction welcome doorbell. Some people say welcome, some people jingle, some people say congratulations on getting rich, and so on. Infrared human body induction greeter is stylish and compact in appearance, portable in design and multifunctional, and can be placed anywhere without any external connection. Voice can be recorded according to your own needs, in any language. As long as a guest comes in, the usher will take the initiative to say hello, which can not only welcome the guests, but also remind the busy shopkeeper that the guests are coming. When a thief steals a shop or living room, he hears an alarm as soon as he arrives at the door, and the timid thief runs away at once.