For use with range hoods and taller 10 to 12-foot ceiling heights. This kit covers exposed running from the hood to the ceiling while providing a finished look to your range hood. Please check the specification sheet to ensure compatibility.aThis duct cover extension kit replaces standard duct covers to accommodate up to a 12-foot ceiling height. This kit covers exposed duct work running from the hood to ceiling while providing a finished look to your range hood. Please check your Zephyr range hood's specification sheet to ensure compatibility.