20x20x5 (4 3/8) Honeywell/Lennox Replacement MERV 13 Air Filters 2 Pack Chemicals Advanced pH electrode diagnostics ensure

Advanced pH electrode diagnostics ensure worry-free measurements

Six individual drying chambers

root rot and root damping-off

Highly reflective and diffuse plastic microfiber seam tape

square pots

20x20x5 (4 3/8) Honeywell/Lennox Replacement MERV 13 Air Filters 2 Pack Chemicals Advanced pH electrode diagnostics ensureImportant 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. We also carry 4 7 8 and 5 1 4 inch depth filters,