The purpose of any exhaust filter is to capture over-spray particles and remove them from the airstream. Exhaust filters play an important role in maintaining proper air flow, cleanliness of exhaust stacks and maintenance of the exhaust system. It is recommended that premium filters be used throughout the paint booth. Improperly maintained spray booths may increase the risk for fires in the booth and may result in non-compliance of emission standards. When filters are used longer than they should, they are saturated with overspray, causing blockage and bad airflow in the booth. This causes an increase in costs from a number of ineffective painting situations. Contaminants blocking the overused filters cause longer drying times and more dirt in the paint jobs, meaning more buffing. There are also more costs for heated equipment because of burner corruption and bad airflow. These are filters designed to be used in a Standard Tools' booth but will work in any style designed to use 20x20x2 dry arrestor exhaust filters. UL Class II, 98.6% efficient and a woven polyfiber. Clean Filters = Clean Air! Change exhaust filters when the manometer reads 0.5" above the initial differential reading.