.... > ....Products > HVAC > Galvanized Duct, Pipe, Fittings and Elbows > Base Cans, Plenums, Filter Frames and Filter Bases > Furnace Plenums > Furnace Plenums – 1" and 2" Insulated > Furnace Plenums - 2" Insulated 23 Plenum > Furnace Plenum, 16 x 20 in, 23 in H