Product review (4 stars): Venta Humidifier Replacement Filter
I'm glad that this filter is still available on-line.  We bought two Venta humidifiers a few years ago at a local store, and at the time they were carrying replacement filters for this brand.  They stopped carrying them recently and this year we thought we were going to have to shell out another $200 + dollars to get the latest humidifiers.

The demineralization filter does a great job of reducing the buildup of calcium, lime, and rust.  It's also convienent to change out.