N95 or 95% filtration is a standard that the mask have to pass to be rated those that pass that test are rated N95 but within that rating there are ones that are made for special purposes. The NIOSH 42CFR 84 Regulation for N95 particulate is the regulation you want to look up to learn more about this. My Graingers catalog lists about 100 masks that meet that reg and several that meet N99 or 99% filtration. Others are even more specialized each with its own purpose. It all depends on what you want it to protect you from. The Grainger web page should have more info on this enough to confuse almost any one. <img src="/images/graemlins/grin.gif" alt="" />