Some plastic thermos bottles have holes at the bottom to filter water.

The small holes in the teapot are mainly used to adjust the air pressure inside and outside the teapot, so that the air pressure inside the teapot is the same as that of the outside atmosphere, so as to prevent the steam inside the teapot from washing away the lid of the teapot and causing danger.

The inner container of the thermos bottle is made of thin stainless steel plate, the port is marked with two triangular full water signs, and the bottom has a small hole connected with the water outlet pipe. The bottom of the tank is equipped with a normally closed temperature jump controller to control the upper limit temperature.