Air Showers are installed at the doorways of Cleanrooms to prevent contaminants attached to workers and materials from being brought into the room. High-speed air cleaned through HEPA filters is blown directly on people and materials to remove attached dust. In addition, there are two doorways, and as these are structured so that they cannot both simultaneously be open, this functions as an airlock insulating the Cleanroom from the outside air. The interior of the Air Shower is structured so that is it typically cleaned when not in use to prevent external contaminant particles from flowing in.
Pass Boxes are double-door box-shaped devices that are used when materials are brought into the Cleanroom. Similar to Air Showers, they are structured so that both doors cannot simultaneously be open, so they function as an airlock insulating the Cleanroom from the outside air. Models featuring Air Shower functions and models featuring Clean Unit functions are also available.