13x21_3/4x1 Exact MERV 14 Plus Carbon AC Furnace Filters 6 Pack Monitors & Timers Precise digital display shows current

Precise digital display shows current temps 24/7

can get up to 2

Designed for use in greenhouses

Manifold Dimensions - 5" x 4" x 3"

13x21_3/4x1 Exact MERV 14 Plus Carbon AC Furnace Filters 6 Pack Monitors & Timers Precise digital display shows currentNordic Pure Custom MERV 14 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