10x33x1 Exact MERV 13 Plus Carbon AC Furnace Filters 6 Pack Growing Accessories Cups are manufactured in Humboldt

Cups are manufactured in Humboldt County

Soluble Seaweed Extract can be stored indefinitely

The ONA Carbon-Air unit is to be used exclusively with ONA Gel

Fast-Acting Results – Begins working on contact

10x33x1 Exact MERV 13 Plus Carbon AC Furnace Filters 6 Pack Growing Accessories Cups are manufactured in HumboldtNordic 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