Air Science® USA. These high-efficiency ductless fume hoods use downward airflow and 2 filters to protect operator and environment from hazardous vapors. With unrestricted front and side access, they are ideal for applications requiring complex, intense operator involvement. The high-capacity air handling system delivers a face velocity of 80 FPM at the work surface. Backed by a 1-year manufacturer warranty (excludes consumables such as filters and lights). Hoods are available in 3 widths, 24", 36", and 48"; internal height, 15-3/4". Mobile carts specially designed for each model are available (sold separately). Allow 6 weeks for delivery. Note: To place an order for these fume hoods you must order filters separately; fume hoods do not include filters. Proper operation requires a pre-filter and main filter(s). For international (220-V) models, select plug type when ordering. Most international plug types are available.