Donaldson Aerospace (Hall 2B, E105) is displaying versions of its two-stage Air Purification System (APS) cabin filter for the Boeing 737, 757, 777 and the Airbus A330 for the first time publicly. APS, which combines a HEPA particulate filter with a chemical-adsorbing carbon stage, is standard on the 787. Donaldson also has a retrofit APS in service for the A320 family.