Standard Bench Mount and Floor Mount hoods with over 40 standard sizes and custom sizes to you specs. UniFlow Superstructure exclusive unitized dual wall construction for total chemical resistance, strength, and durability. Performance tested to ASHRAE 110 - 1995. U.L.1805 Certified for Fume Hoods & Cabinets, and SEFA1 Recommended Practices for Fume Hoods, and Greener Product Certified.