Replaces damaged or worn cartridge filter supports maintains the appropriate level of protection and comfort, specially designed for use with middle reusable masks 3M 7500 series™ pack includes two inhalation valves and one of exhalation fast and simple placement increases the life useful your computer filter from 3M cartridge holder 7586™ is a spare part specially designed for use with middle reusable masks 3M 7500 series™. The pack includes two valves of inhalation and exhalation. Be sure to have the correct level of protection and work comfortably with the support of 3M™ 7586 cartridge filter. It is easy to install and helps increase the life of your half mask of the 7500 series. This replacement cartridge filter holder pack includes two valves of inhalation and exhalation, and is specially designed for use with middle reusable masks 3M 7500 series™.