BUILDMART - 20x12 MUD-IN Air Vent Cover - Drywall Mud-in White Air Vent - Mud Linear Slot Diffuser - Register Grille for Ceiling and Walls - Texas BuildmartOur Standard Linear Slot Diffusers have ASHRAE 70 and ANSI S12. 51 Engineering Certifications Designed and Engineered to the Highest HVAC Industry Standards Commercial Grade Solid Aluminum with Modern Architectural Design This Model can be used in Ceilings and Walls This Model can be used as a Supply Vent Cover and Return Vent Cover CFM: 345 ft3 min Effective Velocity: 9. 8 ft s Neck: 19 9 16" x 11 3 4" Face: 21 5 8" x 13 3 4" This is a Non Filter

Our Linear Slot Diffusers have ASHRAE 70 and ANSI S12

CFM:  ft3/min - Effective Velocity 9

Entry size: 10" flex in oval shape

60" X 3 1/2" Linear Slot Plenum Box - For Double Slot (2 Slot) Linear Diffuser - Texas Buildmart - Modern AC Vent Covers for Ceilings

CFM: 403 ft3/min - Effective Velocity: 9

180° pattern adjustment and complete flow rate control

Here's a link to the Plenum Box that fits this Diffuser:

48" Linear Slot Diffuser - 1 Slot - Single Slot Linear Diffuser - Texas Buildmart - Modern AC Vent Covers for Ceilings

Neck: 21 9/16" x 7 13/16" - Face: 23 11/16" x 9 13/16"

Neck: 29 1/2" x 19 1/2" - Face: 31 1/2" x 21 1/2"

Total Box Dimensions: L: 25 1/16" W: 4 5/8" H: 11 7/8"

24 x 14 24x14 14x24 14 x 24