16_1/4x21_1/4x1 Exact MERV 13 Plus Carbon AC Furnace Filters 6 Pack Terp Derp migration from outside may occur

migration from outside may occur in warmer months

these dampers prevent air leakage into your fan setup

"Easy to set up and the LED panel makes it simple to dial in exactly where I need humidity

Tested: The efficacy of GrowSafe has been studied extensively

16_1/4x21_1/4x1 Exact MERV 13 Plus Carbon AC Furnace Filters 6 Pack Terp Derp migration from outside may occurNordic Pure Custom MERV 13 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