Razer sold the $100 Zephyr mask for only a few months ending in ... to perform to the N95 standard of 95 percent or greater PFE [Particulate Filtration Efficiency]," the lawsuit said.

or fine particulate matter, which is especially dangerous when inhaled, and AQMD officials advise that if residents must absolutely be outside they should consider a P100 respirator or properly ...

This particulate matter can range from clearly ... that ends with a 99 would be 99 percent efficient. A P100 respirator is not 100 efficient because nothing is 100 percent in life.