11_1/2x21x1 Exact MERV 12 Plus Carbon AC Furnace Filters 6 Pack Tents & Tarps Includes (2) EZ Turn duct

Includes (2) EZ Turn duct clamps

and measurable results from the first application

it does double-duty

aquariums & reef tanks

11_1/2x21x1 Exact MERV 12 Plus Carbon AC Furnace Filters 6 Pack Tents & Tarps Includes (2) EZ Turn ductNordic Pure Custom MERV 12 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