Blue Pure 411i (3250i) Max, 411a Max Smokeblock Filter

I use these in my acupuncture clinic to filter the moxa smoke out of the air after being in a small enclosed space with light amounts of smoke and PM2.5s. This filter does an excellent job of pulling those small particles and smoke smell out of the air compared to the regular filters (the data stream in the Blueair app corroborates this). Highly recommended for small, smoky environments.

I have two Blue Air devices. I misplaced one of my auto - delivered filters so I ordered what I thought was a correct replacement. When I received it, I found it did not fit. I wasn't able to use the automated return so I initiated a chat with customer service. I was unable to return the filter because I had opened it. I was refunded the purchase price and was instructed to dispose of the filter. I tried to find someone to give it to but could not. So I purchased the relevant device and gave it along with the filter, to my son. All good 👍