I'm doing fire damaged tree risk assessment in Butte Co California. There's a big problem with smoke from wildfires blowing into the areas where our teams are working. I've found that I can wear my 2.5 all day long, from 7:30am until 5pm or later and still be able to climb up and down inclines to get to sketchy looking fire damaged trees in order to inspect them up close and personal. I also wore it from the time I stepped out of the car onto the sidewalk at Tampa International Airport, until I cleared the car rental location in Sacramento. Ironically, even though I'd purchased the specialized caps to replace the purge valves, the airline staff still required that I wear a paper mask over the RZ 2.5. The airport as well as the planes themselves were full of "Karens" who balked at wearing a mask, even in the close proximity posed by an airliner full to capacity. I'm happy to say that two weeks later I'm healthy as a hog, and seem to have dodged Covid19. I really can't say enough good things about this mask.