20_1/2x25_1/2x1 Exact MERV 8 Plus Carbon AC Furnace Filters 6 Pack Emitters The name "420" references the

The name "420" references the area of the light spectrum produced by this lamp

this versatile tool slices through thick stems and tough roots with ease—perfect for high-volume harvesters working with squash

this product is non-phytotoxic and a good way to provide calcium for growth

Water-resistant housing

Complete control of your grow room from up to 150 ft away without wires

20_1/2x25_1/2x1 Exact MERV 8 Plus Carbon AC Furnace Filters 6 Pack Emitters The name "420" references theNordic Pure Custom MERV 8 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