12_3/4x21x1 Exact MERV 10 Plus Carbon AC Furnace Filters 6 Pack Hydro Components great for use with air

great for use with air or water

meaning you won't need to invest in or calibrate another Oakton pen once you've become comfortable using yours

The unique formulation promotes immediate uptake for hydration and nutrition

TurboKlone is the #1 cloning machine for first time users

Uniform density allows for uniform water levels throughout the product resulting in even crop growth

12_3/4x21x1 Exact MERV 10 Plus Carbon AC Furnace Filters 6 Pack Hydro Components great for use with airNordic Pure Custom MERV 10 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