21_1/4x23_1/4x1 Exact MERV 13 Plus Carbon AC Furnace Filters 6 Pack environmental-controllers IR and UV LEDs bloom

IR and UV LEDs bloom enhancers

Increases resistance to environmental stress

* Chamber: 16*14

it is recommended by top horticultural experts and ideal for a wide range of plants

you can grow with confidence

21_1/4x23_1/4x1 Exact MERV 13 Plus Carbon AC Furnace Filters 6 Pack environmental-controllers IR and UV LEDs bloomNordic 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