I just got 40 for my dad last month from amazon... $16/shipped for 20 can't beat that... He uses them for EVERYTHING. mowing the grass to sanding or dusting the house. Totally allergic to it all.

Me? They do not seal good AT ALL even if you contour them aroudn your nose you still get contaminated goop in.. sure they may have good filtration but not if it doesn't close up the gaps good

I have one of those 3M with the filters onthe side, and the plastic around tnhe face with the straps you adjust.. that thing is great! I use it for painting and other dirty jobs.