The 3M Secure Click Filter Retainer D701 is used to hold 3M Secure Click Particulate Filters D7N11 or D7P71 in place on 3M Secure Click Cartridges D8000 Series. For use with 3M Secure Click Respirators.When certain airborne particulates are present in the work environment in addition to certain vapors or acid gases, a particulate filter may be required. The 3M Filter Retainer D701 allows you to use NIOSH-approved N95 or P95 filters with 3M Secure Click Cartridges D8000 Series. Change 3M respirator filters in accordance with your well-documented change-out schedule or anytime the filters are dirty, damaged, or difficult to breathe through. 3M Select and Service Life Software is a free online tool (www.3M.com/sls) that can help you select the proper respirators, cartridges, and filters for your work environment, as well as manage the service life of your products.