12_3/4x21x1 Exact MERV 13 Plus Carbon AC Furnace Filters 6 Pack spl_hw 0 pounds per acre as

0 pounds per acre as needed

Midges (Chironomus decorus)

when needed

This shutter fan features an EC-motor that is precisely controlled using PWM (Pulse Width Modulation)

Safe power-up/power-down feature protects your equipment

12_3/4x21x1 Exact MERV 13 Plus Carbon AC Furnace Filters 6 Pack spl_hw 0 pounds per acre asNordic 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