21_1/4x23_1/4x1 Exact MERV 12 Plus Carbon AC Furnace Filters 6 Pack Ventilation/Air Conditioning Move table's contents more easily

Move table's contents more easily and prevent spills

Emerald Triangle's ultra-potent PK booster takes it to the next level

high-impact upgrade for any serious grow operation

An exposed temperature sensor allows for rapid automatic temperature compensated TDS/PPM measurements

Anti-Drip Properties

21_1/4x23_1/4x1 Exact MERV 12 Plus Carbon AC Furnace Filters 6 Pack Ventilation/Air Conditioning Move table's contents more easilyNordic Pure Custom MERV 12 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