The Series F72 Air Intake Filter and Filter Silencer is designed to mount directly on the inlet of an engine, blower or compressor. It will provide 16dB to 20dB noise reduction. The Polyurethane filter media has an efficiency of 98% on 10 micron particles and a stainless steel center core. SERVICE LIFE & CLEANING: The service life of the element is dependent upon the surrounding environment and cannot be predicted. To prevent COLLAPSING of the filter element, STODDARD SILENCERS recommends the differential pressure across the filter element NOT exceed 15 inches of water column. Positive indication that the element requires cleaning or replacement can be provided with STODDARD SILENCERS model A40-108 Pressure Drop Indicator, at an extra charge. Wash in sink or large pan using either water and any good washday type detergent and rinse clean. Squeeze out filter by pressing it against metal grid. Let stand and allow to dry completely.