This compact WORKSHOP Standard wet dry vac filter is ideal for most typical dirt, sawdust, and everyday messes. The material captures debris, down to 5 microns at 95% efficiency. Large surface area improves airflow and help resist clogging. Durable material can be washed. WORKSHOP recommends replacing your wet dry vacuum cleaner filter at least twice a year to keep your shop vacuum working at its optimum level. Fits: WORKSHOP 3-4.5 gallon wet dry vacuums and the 5-Gallon WS0500VA