17_1/2x21x1 Exact MERV 13 Plus Carbon AC Furnace Filters 6 Pack -monitors-&-timers pH Combo Electrode Glass Body

pH Combo Electrode Glass Body - Refillable Temp Sensor

6" flanges for straight through fan-powered supercooling capability

Bulb: DE HPS/MH

Active Aqua Hydrologic brand booster pump for the Merlin Reverse Osmosis filtration system

17_1/2x21x1 Exact MERV 13 Plus Carbon AC Furnace Filters 6 Pack -monitors-&-timers pH Combo Electrode Glass BodyNordic 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