The white disc on the ceiling can't be painted.

The white disc on the ceiling needs no coating. This is a smoke alarm.

Smoke detector is actually another name for smoke detector or smoke detector.

Smoke detectors can prevent fire by monitoring the concentration of smoke. An ion smoke sensor is used inside. Ion smoke sensor is a kind of sensor with advanced technology and stable and reliable work, which is widely used in various fire alarm systems, and its performance is far superior to that of gas-sensitive resistance fire detector. This smoke detector is the first domestic detector to obtain the latest 3C certification, and it is recommended to fire brigades all over the country. Its installation is simple and the effect is remarkable. It has been widely used in homes, factories, office buildings, hospitals, schools, museums and other important fire prevention places.