18x27x1 Exact MERV 7 Plus Carbon AC Furnace Filters 6 Pack Cloning & Seed Starting It’s long lasting

It’s long lasting

textured steel housing

BNC Terminal (left) allows Direct Connection to pH Sensor

We carefully lay out and cut the paper properly with the grain so they roll smoothly (instead of squaring as many other tips from inferior companies do)

18x27x1 Exact MERV 7 Plus Carbon AC Furnace Filters 6 Pack Cloning & Seed Starting It’s long lastingNordic 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