Breathing Filters Code Description Case Quantity 1944 Filta-Guard™ 99.999% BFE/VFE Resistance wet/ dry 2.3 cm H20 40 1844 Clear-Guard II™ 99.99% BFE/VFE resistance wet/dry: 2.3 cm H2O 50 1644 Clear-Guard Midi™ 99.9% BFE resistance wet/dry: 2.1 cm H2O 50 1844-P Clear-Guard II™ with port, 99.99% BFE/VFE,resistance wet/dry: 2.3 cm H2O 50 1844-PT Clear-Guard II™ with port and flextube, 99.99% BFE/VFE,resistance wet/dry: 2.3 cm H2O 20