16x20x4 (3 5/8) Pleated Air Filters MERV 15 Plus Carbon 1 Pack hydro-systems Designed exclusively for Hydrofarm by

Designed exclusively for Hydrofarm by America's foremost lighting design engineers

Made of galvanized steel for maximum resistance to rust and corrosion

The integration of ballast and reflector results in a compact fixture

This easy to use concentrate is ideal for controlling and preventing powdery mildew

Open design delivers maximized light output and optimal heat management

16x20x4 (3 5/8) Pleated Air Filters MERV 15 Plus Carbon 1 Pack hydro-systems Designed exclusively for Hydrofarm byImportant 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