9_3/4x23_3/4x1 Exact MERV 7 Plus Carbon AC Furnace Filters 6 Pack Air Purification The pyrethrins attack the nervous

The pyrethrins attack the nervous system of the insect while the B

Built-In Photocell Detecting Day/Night Mode

The rechargeable battery lasts for up to 8 hours after a full charge

Pre-amplified pH Electrode

Great for environmental and agricultural testing

9_3/4x23_3/4x1 Exact MERV 7 Plus Carbon AC Furnace Filters 6 Pack Air Purification The pyrethrins attack the nervousNordic Pure Custom MERV 7 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