The innovative 3M™ Secure Click™ platform features a quick, simple cartridge/filter connection. It works just like a seat belt. Simply align the connections and push until you hear a click and feel confident that filters are installed properly. Two dual-flow filters on each respirator combine to create four airflow paths in the world’s first quad-flow cartridge/filter system, providing great breathability and comfort. Swept back filter design offers compatibility with certain welding and grinding shields. 3M™ Secure Click™ Particulate Filters are NIOSH-approved for use with 3M™ Secure Click™ Reusable Respirators HF-800 and FF-800 Series and provide protection against a wide range of dusts, mists and other particles. 3M™ Secure Click™ Particulate Filters D9000 Series are encapsulated in hard plastic cases to help protect them from damage, dirt, decontamination spray showers, debris, spark