Review on Aprilaire - 35 A4 35 Replacement Water Panel for Whole House Humidifier Models 350, 360, 560, 568, 600, 600A, 600M, 700, 700A, 700M, 760, 768 (4-Pack) by Chris Pinkney

A lot and they work great. Everywhere I've installed a humidifier like the Aprilaire 700, I've had static issues. The mechanic told me to use Aprilaire filters, not aftermarket filters which are cheaper and widely available. On a recent visit he showed me that they are a little thicker and made differently so they hold water better. Since I've been using them the static has gone and when I tested them I saw that they actually hold a lot more water and last a lot longer. Another example of getting what you pay for is buying the right product.