12_3/4x20_3/4x1 Exact MERV 13 Plus Carbon AC Furnace Filters 6 Pack cleanroom Listed diameter is measured from

Listed diameter is measured from the inside of the bottom of the saucer

and the 2 1/4" Matrix Circulator

Apply weekly and on the same day and time each week

and are immediately ready to use by a grower upon receipt

Working Environments:                 Temperature 32-122°F

12_3/4x20_3/4x1 Exact MERV 13 Plus Carbon AC Furnace Filters 6 Pack cleanroom Listed diameter is measured fromNordic 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