3M Secure Click Organic Vapor/Acid Gas Cartridge D8003 has the Secure Click connection style. The 3M Secure Click connection style enables a quick, simple connection of the cartridges. Simply align the connections on the facepiece and cartridge and push until you hear a click. The innovative Secure Click connection helps provide wearers confidence that the cartridges are installed properly. Also, the Secure Click cartridges are dual-flow to allow easier breathing. Two dual-flow cartridges on each respirator combine to create four airflow paths in the world’s first quad-flow cartridge system, providing greater breathability and comfort.