This purifier is brand new except for my trying it at one night. Whilst works actually quietly, it is not as totally silent as I hoped that it would be. Due to my own extreme noise sensitivity when sleeping I decided that it was not for me. Hence my listing it here. I am sure though that a good sleeper has nothing to worry about.

You can breathe clean air with this air purifier
It is able to help reduce allergy symptoms, eliminate pollution, improve blood circulation, rest and much more. 
It is recommended to change the filter every 6 months.
Filters 99.7% of dust particles, smoke, pollen, pet hairs helping to combat some of the symptoms of allergy.
It operates very quietly, so unless as absurdly noise sesitive as this seller you can use it at night without disturbing your sleep.
It has an LED display for easy operation.
Being portable, you can take your Air Protect Pro from room to room as needed.