Telescoping inner and
outer aluminum box
Unpainted aluminum louvered
inlet grille with internal bug screen
3 1/2"
A
Front View
Weep holes
2 5/8"
4" to 8"
1/2"
2 13/16"
Side View
Dimensions and data
Outside air wall box
Dimensional data
Model
A
Rough opening
WB-0203
24
22-1/2 x 3
WB-0406
29
27-1/2 x 3
WB-081012
39
37-1/2 x 3
21