We know buying replacement filters for your home or business can be a challenge, especially if it's your first time. That's why we offer our Purchase Guarantee. We make your purchase risk free with these features.
!The filters below are in stock, and 100% compatible with part number WF40
Save Your Furnace Tip #4:
MERV stands for Minimum Efficiency Reporting Value, and measures a filters’ efficiency in removing small particles. The higher the MERV rating, the more particles the filter can remove.