This 4-pack of RIDGID Pleated HEPA Filter's are designed to fit most RIDGID wet/dry vacuums (5 Gal. and larger) to capture wet and dry messes. The HEPA Filter is 99.97% efficient at filtering dry particles 0.3 micron or larger. Increase your filtration level on the jobsite with this HEPA filter. During your heavy-duty project cleanups, the filter can be used to capture dry messes such as drywall dust, sawdust and mold as well as liquid spills and waterborne debris. The durable, strong material allows for wet and dry messes to be picked up without switching between a dry and wet filter - saving you time and energy. With the Qwik Lock feature, the wet/dry vac filter simply snaps on or off the shop vacuum for easy cleaning and this replacement filter can also be washed and reused for extended uses. Changing RIDGID shop vac filters often is strongly recommended to increase the vac's performance and to help extend vacuum life as it protects the motor from harmful debris. Pair filter with a RIDGID dust bag (VF3502 or VF3503, sold separately) to contain dry dust and debris and for easy disposal. RIDGID wet dry vacs provide a wide range of filtration and attachment options so that you can customize to the job at hand.