Class M vacuum cleaners are designed for more hazardous dust types, such as quartz dust, hardwood, concrete, brick, filler, paint, or metal dust. They filter at least 99.9% of the vacuumed material and are mandatory on many construction sites and in the trades. The vacuum cleaner must be equipped with a volume flow monitor, and the operator must be trained annually (Section 11 of the Austrian Association of Dust Collectors). Ideal for interior design, renovation, painting, woodworking, and construction.