Lightweight frame with reusable disposable N99 rated filters. Full 8 hours of use per filter for all day protection. 99%+ filtration efficiency. Captures dust as fine as 0.3 microns at 11 gallons per minute. Suitable for all woodworking tasks, masonry and demolition work, fiberglass, mixing concrete, mortar and plaster, welding, hand and power sanding and many more.