BUILDMART - 48" Plenum Box for [48" Linear Slot Diffuser - 1 Slot - Single Slot] Premium Insulated Plenum Box for Heating and Cooling

Ideal for Texas Buildmart 48" Lineal Slot Diffuser - 1 Slot Galvanized sheet metal Plenum Box with foam insulation Total Box Dimensions: L: 48 1/2" W: 3" H: 12" Mouth Dimensions: L: 47 9/16" W: 1 3/4" Entry size: 2 entries of 8" flex in oval shape This air-distribution box attaches directly to the supply of the HVAC equipment that heats or cools the air If you do not have this size flex, you can use a reducer to modify the size