Plenum Supply Un-Lined 1 6 X

Supply Plenum 16-3/4 X 1 4 X

Supplyplenum 16-3/4 X17-

Supply Plenum 16-3/4X21-

Supply Plenum 16-3/4X24-

Supply Plenum 12 X 14-3 /8 X36

Supply Plenum 12 X 17-7 /8 X36

Supply Plenum 12 X 21-1 /2 X36