How to write the office knock sign?

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 "The air conditioner is on, please close the door behind you, thank you". You can also let him customize it as a reminder of other content. It can also be achieved. If the door opens and closes within five seconds, there will be no warning. If it is not closed after five seconds, it will remind you, which is very convenient and practical.