21x23_1/2x1 MERV 8 AC Furnace Filters 6 Pack X Nutrients Engineered with Swiss-made thermalloy probe

Engineered with Swiss-made thermalloy probe heads offering precise temperature and humidity measurements

Contains no genetically modified organisms (GMO)

Replacement sensor for Oakton Waterproof Multiparameter TestrTM 35-series Pocket Meters (OK3542500 and OK3542505)

100% naturally occurring bat guano

Humboldt Nutrients Bloom Natural is an ultra-concentrated natural bloom formula designed to give your plants the large phosphorus and calcium boost needed during the flowering period

21x23_1/2x1 MERV 8 AC Furnace Filters 6 Pack X Nutrients Engineered with Swiss-made thermalloy probeNordic Pure MERV 8 Pleated AC Furnace Air Filters provide exceptional filtration for both home and commercial environments. Each time air passes through a Nordic Pure pleated furnace air filter, lint, dust, pollen, bacteria, pet dander, dust mites, mold spores and other contaminants are removed. MERV 8 furnace filters are comparable to HVAC filters with the rating of MPR 800. While different companies use different scales to measure the air filters