LabGard model NU-427 is a NSF/ANSI 49 Listed Class II, Type B1 Biological Safety Cabinet (BSC) providing personnel, product, and environmental protection. Personnel protection is created through an air barrier at the front of the cabinet. Product protection is created through HEPA filtered laminar airflow over the work surface. Environmental protection is produced by HEPA filtering exhausted air before entering a facilities exhaust system. LabGard model NU-427 recirculates 30% and exhausts 70% of air. Model NU-427 must be ducted to a dedicated facility exhaust system.