12_3/4x20_3/4x1 Exact MERV 7 Plus Carbon AC Furnace Filters 6 Pack Grow System/ Trays/ Reservoirs Large-scale greenhouse operations requiring consistent

Large-scale greenhouse operations requiring consistent

Light Penetration

ergonomic design with comfy arm rests

and pollinators

The most stable output frequency of any ballast

12_3/4x20_3/4x1 Exact MERV 7 Plus Carbon AC Furnace Filters 6 Pack Grow System/ Trays/ Reservoirs Large-scale greenhouse operations requiring consistentNordic Pure Custom MERV 7 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