17_1/4x19_1/4x1 Exact MERV 12 Plus Carbon AC Furnace Filters 6 Pack chillers-heaters-and-purification and BPA-free

and BPA-free

These industrial combination pH or ORP sensors use the conventional measurement technique

two-button meter operation and advanced features

Designed for optimal ergonomics

Each Nordic Pure 4” MERV 7 air filter captures airborne particles as small as 3

17_1/4x19_1/4x1 Exact MERV 12 Plus Carbon AC Furnace Filters 6 Pack chillers-heaters-and-purification and BPA-freeNordic 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