FlexFit articulating harness is responsive to the motion of the user's shoulders, back and hips, increasing comfort and reducing fatigue. Triangular shape conforms to the back for a closer fit, reduces accidental contact with walls and doorways. The die-cast aluminum tri-latch system assures air performance. Stay cooler, open weave harness allows any heat to dissipate. Four level filtration with HEPA captures 99.97% of particulates 0.3 microns or larger, improving IAQ. Four Level Filtration w/HEPA: 1372 sq in total area.