Portable Grade D filtration system designed to provide breathing air for a specific number of workers. Filters incoming air from compressor to Grade D quality air and monitors for CO and/or O2. First stage element filters bulk water and particulate and has an auto drain. Second stage coalescing filter eliminates atomized oils, mists, ultra-fine particulates and has an auto drain. Third stage filter removes organic vapors and odors and has a manual drain. Filter change indicators are standard. Use in the upright and closed position. Meets or exceeds OSHA 1910.134 standards. Rental available daily, weekly or monthly.