SEBO 7029ER Filterbox for Felix Vacuum,8 Pack
Top-fill, three and four-layer bags are an integral part of SEBO's filtration system because they hold virtually all dirt captured by the vacuum, which improves the effectiveness and useful life of the microfilters.  They also ensure continuously strong suction because dirt enters from the top, deposits at the bottom, accumulates upward, and air exits through the sides, which allows  unimpeded airflow as they fill to capacity.