Return Air Grille for and 18" x 18" opening. 21" x 21" overall size. Square design. Black finish. - Majestic Vent Covers
Proper Selection & Sizing of Return Air Grilles - YouTube
Cast Aluminum Air Return Grill 6″ x 28″ inch | Hand Finished Floor Register Cover for Home Decor | Floor Registers and Grills
Air Vent Covers, Metal Air Vent Covers | James Gilbert and Son
Air Vent Grille |Premium luxury finish and modern design – SABA Home Decor
26" x 20" Return Air Grille - Sidewall and Ceiling - HVAC Vent Duct Cover Diffuser - [White] [Outer Dimensions: 27.75w X 21.75"h] - Walmart.com
15cm,20cm,25cm,30cm,40cm,50cm Aluminum Alloy Air Vent Perforated Sheet Web Plate Ventilation Grille - Vents - AliExpress
Custom Pro-Linear Vent Cover Return Air Filter Frame (White) - 23.5" x 23.5" opening size (26-1/8” x 26-1/8” overall size) With mounting holes - Vent and Cover
Shop By Size - Decorative Vent Covers Vent Covers Unlimited
10"w X 6"h Steel Return Air Grilles - - HVAC Premium
Custom Air Vent Cover Mandala Return Air Vent Cover - Etsy
26" x 20" Return Air Grille - Sidewall and Ceiling - HVAC Vent Duct Cover Diffuser - [White] [Outer Dimensions: 27.75w X 21.75"h] - Walmart.com
Got Standard Register Sizes HVAC Questions? (We've Got You Covered) – Reggio Register
MroMax 9.84" x 3.15" (LxW) Air Vent Aluminum Alloy Square Ventilation Grille Cover 250mm x 80mm Rectangle Air Grille for Walls and Ceilings HVAC Cabinets 2Pcs - Amazon.com
Other Large and Odd Sized Floor Vent and Return Sizes
SMI Ventilation Products Victorian Base Board 6 in. x 22 in. Opening, 8 in. x 24 in. Overall Size, Polymer Decorative Return Air Grille, White VBB622 - The Home Depot
Custom Vogue Vent Cover Supply (White) - 10" x 7" opening size (12" x 9" overall) with mounting holes, with air deflector - Vent and Cover
150mm Width Vents Perforated Sheet Aluminum Air Vent Ventilator Grille Cover Ventilation For Closet Shoe Home Decor Cover - Vents - AliExpress
Decorative Air Vent Cover. Made in UK P43r Size 395mm X - Etsy
Venti Air 8 in. Wide x 24 in. High Return Air Filter Grille of Steel in White HFG0824 - The Home Depot
Grille for 30" x 20" rough opening, overall size 32" x 22"