Using your DeWalt DCV5011H HEPA filter set is easy. First, turn off and unplug your DCV501HB hand vacuum. Then, open the filter compartment and remove the old filter. Insert one of the new HEPA filters from the set into the compartment, making sure it fits snugly. Close the compartment. Now your vacuum is ready to use with enhanced air - cleaning power. When using the vacuum, avoid using it in extremely dusty areas for long periods as this can reduce the filter's lifespan. For maintenance, check the filter regularly. If it looks dirty or clogged, replace it with the second filter from the set. You can buy additional sets as needed to keep your vacuum running at its best.