What is the sign for closing the door, please?

You can search for "closing reminder" on Taobao. The closing reminder produced by Sichuan Foster Electronics can be customized according to your requirements, such as "Please close the door after the air conditioner is turned on, thank you". You can also ask him to customize it as a reminder of other contents. It can also be achieved. If the door opens and closes within five seconds, it will not be reminded. If it is not closed after five seconds, it will remind you, which is very convenient and practical.