A replacement for one of the two filters in the AD350 Fume Extractor. The Combined filter includes both a HEPA filter and an activated carbon filter. The HEPA filter collects and removes particulates from the air that are much finer than the pre-filter is able to. It is pleated with webbing between the pleats that prevents airflow vibration or collapse of the filter. The activated carbon filter absorbs contaminants and odors with great efficiency by compacting several pounds of carbon pieces, which vastly increases the surface area, and so effectiveness, of the filtration.
The HEPA filter boasts an efficiency of 99.997% at 0.3 microns. The carbon filter includes 19 lbs of activated carbon. Both are combined into a single unit, which is recommended to be replaced every 12 to 18 months.