I was so glad to have it, especially when we got stuck on the runway for an hour, when filters are usually off and there’s no ventilation. It’s great to have something with you that might make a difference rather than just being stuck there, helpless. Used it again on bus/train rides, especially with audibly sick people coughing all around me. In theses cases, I held it close to my face – which also makes it function like a fan, cooling you off (I get hot in N95s). Airline stewardesses were curios about it but they didn’t make me put it away, even during take off and landing. I carried a cell-phone battery pack for running it for a long time (eg 10 hour flight), but the battery in it lasts pretty well too – useful for those moments the airline stewardess doesn’t want anything plugged into the USB ports. It’s very light weight and no problem to hold it for long periods of time.

Dear SmartAir: this thing rules, but those two little plastic pieces that can fall out of position when it’s turned on its side should get redesigned so they can’t fall. In fact, this was used in every position and orientation possible, so designing for that possibility would be good. Also, the strap came off immediately, and the peg to hold it was instantly lost. Overall, though – a lightweight little filter, quiet, USB2 cable – very useable device.