The RIDGID HF1000 (40068) HEPA Filter with Pre-Filter is 99.97% efficient at filtering particulates down to 0.3 microns in size when used in conjunction with the RIDGID RV2400HF Wet/Dry Vacuum. When used with the RV2400HF, the vacuum system is HEPA certified for EPA cleanup under the remodel, repair, and painting (RRP) rule. The filter is water resistant and durable for easy cleaning and reuse. The included Pre-Filter is a washable and reusable fabric filter cover that blocks a large portion of the material that might otherwise clog the Certified HEPA filter.