Largest inlets accommodates newest Tumbler Dryers with largest ducts. Fiberglass or Stainless Steel Construction. Non-Corrosive components, no mild steel! Smallest footprint per CFM. 30% thicker Fiberglass body. Dryer backpressure is continously monitored by pressure transducer wihtout any dryer interconnection. When backpressure reaches a level set by user, the lint filter automatically blows clean with compressed air. When the filter senses a complete absence of backpressure indicating that all Tumbler Dryers are switched off, it will blow down for maximum cleaning.