Product review (5 stars): much cheaper, fits and works fine
You know what the mfg is holding you up for these filters, right?  Water Sentinel WSG works fine and is built the  same as my WMF ones at so much less BUT they are a little more difficult to install.  Put a thick bath towel under your work area, get up close and study the placement before you shove and twist it in.  Have faith... they fit and the little extra fuss and mess is well worth the savings especially if you get super saver shipping.