@Momingmom sorry, but a missing CADR rating is a major red flag.
Clean Air Delivery Rate is the industry standard for measuring how fast a purifier can clean the air of smoke, dust, and pollen.
It's a voluntary certification in the US, but most reputable brands get it. When a manufacturer doesn't provide a CADR rating, it's often because their unit's performance is not very good.
It can also mean the purifier uses a technology that CADR doesn't measure, like ionization or UV-C, but in that case, they should be transparent about it