Optimized top filtration basket with 100 th more prefiltration area. Filter material included.Remove the old filter basket and install the new one in its place.Optimizes the pre-filtration of CristalProfi e 401, 701, 901, 1501 and 1901 filters, which then become technically identical to the JBL 402, 702, etc.Ingenious, 2-part filter basket. The removable bottom contains a 35 ppi (fine) post-filtration. The top basket contains a one-piece pre-filtration plate with 100% higher surface area and 15 ppi porosity.Contents: 2-piece filter basket (separable at the clip), with fine and coarse filter foam plates.