MSA's ExtendAire Systems are Emergency Breathing Supply System (EBSS) accessories that use intermediate pressure air to provide firefighters with a source of emergency breathing air. The ExtendAire system allows firefighters to quickly and easily connect to and breathe from a fellow firefighter's air cylinder. ExtendAire Systems are tightly integrated with the SCBA to provide unrestricted mobility and easy access during critical situations. The system uses a quick connect with an integrated check valve that prevents the breathing air pathway from being contaminated by ambient air.