Product review (5 stars): Replacement for Aprilaire humidifier filters
<a data-hook="product-link-linked" class="a-link-normal" href="/Aprilaire-Furnace-Pad-fits-110-550-550A-558-10-A/dp/B000I0PJWG/ref=cm_cr_arp_d_rvw_txt?ie=UTF8">Aprilaire Furnace Pad fits 110,550,550A,558 (10) A</a>Very satisifed with this product.  Just bear in mind that it is a replacement for the manufacturer's brand and is not from Aprilaire.