The Moldex Dirt Dawgs are half mask respirators designed with an exclusive Dura-Mesh shell to keep the filter cleaner so it lasts longer. The wearer will use less filters over time, saving on costs. The Dura-Mesh shell will hold its shape even in hot and humid conditions. Dirt Dawgs particulate respirators are ideal for dusty environments with no oils present. These Dirt Dawgs respirators are designed for comfort with a molded nose bridge that does not need to be adjusted. Dirt Dawgs respirators are NIOSH certified for a filter efficiency of 95% or more for non-oil based particulates.