Benchvent fume filtration hoods and cabinets benchvent bv660h c the techflo filtration systems fume cabinet bv660h c is a circulatory fume filtration hood and cabinet with an air capacity of 355msup3hr that is ideal for use where contaminant capture and filtration are required but where external venting is impractical two stages of filtration hood lighting and a clear polycarbonate panel that helps protect the operator go towards making this fume cabinet suitable for the filtration of