Sturdy build quality and well designed two stage Hepa filter. The original lasted just over one year and I could have stretched that to 15 months easily, but better safe than coughing. These are rated as the best at air filtration and we have been happy with Blueair quality, build, performance, This unit has not been turned off in the last 13 months and has worked silently and flawlessly.

I like the fact this is not overpriced and it's the same brand as the company that built the filter. Fit and function are pretty much guaranteed.

I’ve been consistently happy with my blue air machines and filters for five years.
I own three

These filters are very easy to use and replace. They are somewhat expensive, especially if you have to replace them often depending on your air quality. They do work well though. You can feel the weight difference between the old filter and a new one so I know it is picking up on tons of particles.

Performs as promised! I bought a second one!

Made and recommended by the purifier's manufacturer, these are high quality replacements. Yes, they are expensive, but going "cheap" resulted in clogged filters and an indication within 1 month that they were not functioning. I decided that if I spent what I did for the purifier to protect me and my family, spending a little more for best filters was worth it.