21x23_1/2x1 MERV 10 Plus Carbon AC Furnace Filters 6 Pack AIR FILTER BOXES Combination (full-cell) pH electrode for

Combination (full-cell) pH electrode for field applications with the HI 9815 Turtle pH transmitter

Helps prevent wind damage and thefts

Add Coco-Wet to all your foliar sprays

fill and plant

21x23_1/2x1 MERV 10 Plus Carbon AC Furnace Filters 6 Pack AIR FILTER BOXES Combination (full-cell) pH electrode forNordic Pure Custom MERV 10 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