21_1/4x21_1/4x1 Exact MERV 12 AC Furnace Filters 6 Pack cloning-&-seed-starting When its built-in sensor senses

When its built-in sensor senses that the room temperature has exceeded the setpoint by at least 1°F

which prevents oxidation and freezer burn

Made from Ascophyllum nodosum

blood sucking insects but gentle enough to use on animals with sensitive skin

21_1/4x21_1/4x1 Exact MERV 12 AC Furnace Filters 6 Pack cloning-&-seed-starting When its built-in sensor sensesNordic Pure MERV 12 Pleated AC Furnace Air Filters provide exceptional filtration for both home and commercial environments. Each time air passes through a Nordic Pure pleated furnace air filter, lint, dust, pollen, bacteria, pet dander, dust mites, mold spores, smoke particles, virus carriers, allergens and other contaminants are removed. MERV 12 furnace filters are comparable to HVAC filters with the rating of MPR 1500 1900. While different