21_1/2x23_3/8x1 Exact MERV 7 Plus Carbon AC Furnace Filters 6 Pack AIR FILTER BOXES NEW from General Hydroponics

NEW from General Hydroponics

Lip height is 3 inches

and maximize crop yields

-automatic air pressure compensation valve

21_1/2x23_3/8x1 Exact MERV 7 Plus Carbon AC Furnace Filters 6 Pack AIR FILTER BOXES NEW from General HydroponicsNordic Pure Custom MERV 7 Plus Carbon air filters are made based on the actual measurements so be sure to measure your current filter to get the EXACT dimensions before ordering. As with all Nordic Pure filters, the effective life of your filter depends on the environment in which you live. We recommend changing 1 and 2 filters every 30 90 days. Our 4, 5 and 6 inch thick filters could last up to 6 months. EXACT MEASUREMENT: Furnace and air condition