With the approximately 100% larger pre-filter surface of the JBL Combi Filter Basket II this replacement kit can even be used with older filter models.JBL Combi Filter Basket II+ optimised top filter basket with 100% more pre-filter surface including filter material+ remove previous filter basket and insert new filter basket+ optimises pre-filtering with JBL CristalProfi e 401, 701, 901, 1501 and 1901, which then are technically identical with JBL 402, 702 etc.+ cleverly designed two-part filter basket+ lower removable part contains post-filtering with 35 ppi (fine)+ upper filter basket contains one-piece pre-filter mat with 100 % more surface and 15 ppi pore size+ package contents: 2-part filter basket (separable through clip) with fine filter mat and coarse filter mat+ suitable for CristalProfi e401, e701, e901+ suitable for CristalProfi e1501, e1901