Determining Proper Filter Size
A common mistake when ordering replacement baffle filters is reversing
dimensions. Filters should be placed inside the canopy hood with the baffles
running vertically. The vertical dimension always comes first when placing an
order. The horizontal dimension is the second number. See below for examples on
determining filter size:

Filters should fit snuggly next to each other and cover the length of the grease
trough. Little, if any at all, space should remain once the trough is filled
with filters.