20x24x 1/2 Half Inch Ring Panel MERV 12 Furnace Air Filters 12 Pack CO2 pre-amplified multiparameter probe with internal

pre-amplified multiparameter probe with internal temperature sensor

as some are attractants

Is clear when applied so it won't discolor plant parts

Once in calibration mode submerge the probe in 1382 ppm calibration standard

20x24x 1/2 Half Inch Ring Panel MERV 12 Furnace Air Filters 12 Pack CO2 pre-amplified multiparameter probe with internalNordic Pure Half Inch Ring Panel AC Furnace Air Filters consist of an internal frame bonded between flat layers of two different types of electrostatically charged HVAC furnace filter media. The first layer is a high capacity, polyester filter material which acts as a pre filter, capturing large airborne particles. The second, more efficient, layer is a MERV rated smooth poly blend filter material. The electrostatic charge works as a magnet to draw in