20x21_1/2x1 Exact MERV 12 Plus Carbon AC Furnace Filters 6 Pack spl_hf and a convenient collapsible design

and a convenient collapsible design that features BPA free canvas and a soft carrying case that makes it easy to store and ship

and high output in any growing environment

and landscape plants

It is also highly effective at preventing and controlling fungal diseases like rusts

20x21_1/2x1 Exact MERV 12 Plus Carbon AC Furnace Filters 6 Pack spl_hf and a convenient collapsible designNordic 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