BUILDMART - 36" Plenum Box for [36" Linear Slot Diffuser - 1 Slot - Single Slot] Premium Insulated Plenum Box for Heating and Cooling

Ideal for Texas Buildmart 36" Lineal Slot Diffuser - 1 Slot Galvanized sheet metal Plenum Box with foam insulation Total Box Dimensions: L: 36 7/8" W: 3" H: 12" Mouth Dimensions: L: 35 9/16" W: 1 3/4" Entry size: 10" flex 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