BUILDMART - 18" Plenum Box for [18" Linear Slot Diffuser - 2 Slot - Double Slot] Premium Insulated Plenum Box for Heating and CoolingGalvanized sheet metal Plenum Box with foam insulation, ideal for Texas Buildmart 18" lineal slot diffuser. This air distribution box attaches directly to the supply of the HVAC equipment that heats or cools the air. Connects to: 8" flexible duct in oval shape. Can be used and brazed to a 4" or 6" wood stud. If you do not have this size flex, you can use a reducer to modify the size. Professional HVAC Installer is Recommended. Ideal for Texas

Neck: 23 3/4" x 1 5/8" - Face: 25 1/16" x 3 1/16"

CFM: 449 ft3/min - Effective Velocity: 9

Neck: 5 3/4" x 3 7/8" - Face: 7 7/8" x 5 7/8"

ASIN: B09JB8695C

Entry size: 10" flex

ASIN: B09GPX2P5G

ideal for Texas Buildmart 48" lineal slot diffuser

ASIN: B09GPYGTLB

25 x 24 25x24 24x25 24 x 25

ASIN: B09WT8TRRW

Ideal for Texas Buildmart 60" Lineal Slot Diffuser - 3 Slot

25 x 6 25x6 6x25 6 x 25