Let the old people listen to their lectures every day, and then give them something to eat for several days. While introducing how good their products are, they also talk about some health preservation theories. My family has such a "little black room". Every day, all the people are crowded with old people, and there are even long queues. It's also free lectures and free trials, and then it's also to promote their so-called products or services. Obviously, it is as deceptive as what beds 3 15 sells. I guess someone reported it closed a few days ago.