17x21x1 Exact MERV 13 Plus Carbon AC Furnace Filters 12 Pack bloom A duct muffler designed for

A duct muffler designed for use with inline fans in grow tents

All filters are maintenance-free and feature long-lasting activated virgin charcoal that keeps your air odor-free

Contains Pyganic®

or all at once for dryland farming

Poly greenhouses also have fewer shade spots due to fewer structural requirements than plastic panel greenhouses as well as better overall material longevity for setup and takedown

17x21x1 Exact MERV 13 Plus Carbon AC Furnace Filters 12 Pack bloom A duct muffler designed forNordic Pure pleated AC air filters are made of electrostatically charged synthetic materials that attract and capture most airborne particulates in your home or office. Each time air passes through a Nordic Pure pleated furnace filter, lint, household dust, pollen, dust mites, pet dander, baking flour, mold spores and other contaminants are removed. Our filter media prevents the growth of bacteria or mold, resulting in a much healthier living space.