17_1/2x21x1 Exact MERV 13 Plus Carbon AC Furnace Filters 6 Pack -monitors-&-timers Retractable

Retractable

which modifies flow rates from 0-50 gallons per hour with a simple turn of the key

Oil Applicator/Reservoir

where space is an issue restricting artificial light

depending on crop/deficiency levels

17_1/2x21x1 Exact MERV 13 Plus Carbon AC Furnace Filters 6 Pack -monitors-&-timers RetractableNordic 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