17_1/4x19_1/4x1 Exact MERV 13 Plus Carbon AC Furnace Filters 6 Pack hydro-systems Low range measurement (μS/cm and

Low range measurement (μS/cm and ppm)

handles wood from 1/8 in

or a greenhouse grow setting

• World's finest European reflective specular aluminum: 99

17_1/4x19_1/4x1 Exact MERV 13 Plus Carbon AC Furnace Filters 6 Pack hydro-systems Low range measurement (μS/cm andNordic 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