21x21x1 MERV 13 Plus Carbon AC Furnace Filters 6 Pack leds 0-hour REI (Restricted Entry Interval)

0-hour REI (Restricted Entry Interval) and 0-day PHI (Post Harvest Interval)

Hanging hardware kit

To experience awesome yields

spray product im¬mediately after general watering or irrigation

21x21x1 MERV 13 Plus Carbon AC Furnace Filters 6 Pack leds 0-hour REI (Restricted Entry Interval)Nordic 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