36" Linear Slot Diffuser - (3 Slot) Triple Slot - White Decorative Air Vent - Modern AC Vent Cover for Ceiling, Walls & Floors - Texas Buildmart. Update any room with our modern ac vent covers. Cfm: 389 ft3/min - effective velocity: 9.8 ft/s; neck: 35 3/8" x 4 11/16" - face: 36 13/16" x 6 1/16" (The neck is the section that goes into the vent hole while the face is what will actually cover).
eBay