16x20x4 (3 5/8) Pleated MERV 10 Air Filters 1 Pack -monitors-&-timers 1/4 NPT brass bottom connection

1/4 NPT brass bottom connection and brass internal mechanism

but functions like a microscope

the Dosatron operates by using water pressure as the power source (no electricity needed)

Bluelab® pH Controller Connect™

an 8 oz package makes up to 800 gallons and a 2 lb package makes up to 3200 gallons

16x20x4 (3 5/8) Pleated MERV 10 Air Filters 1 Pack -monitors-&-timers 1/4 NPT brass bottom connectionImportant Note: Almost ALL furnace filters have a different "actual size" than the nominal size printed on the air conditioner filter. It's best if you measure your air filter for the EXACT size and compare it to our "Actual Size" and then you can be sure your A C air filter fits! With the 4" and 5" air filters there is a wider variance between the nominal and actual size depending on the manufacturer. If you are replacing a 4 3 8 depth 16x20x4 filter