This is an air purifier using a HEPA filter and 120mm fan.
Please insert the model printed with the filter rolled on. No adhesive is needed. Then use a fan to expel the air.
The filter uses 400mm x 300. The air in the bedroom is sufficiently clean.
Due to the nature of DC fans, the airflow is low. They are not suitable for large rooms.
https://ja.aliexpress.com/item/1005001619559275.html
The author marked this model as their own original creation.