Achtek 4" Duct Opening Solid Cast Aluminum Round Grille (5-1/2

METAL: Solid Sand Cast Aluminium with face plate thickness of 1/4 Achtek 4" Duct Opening Solid Cast Aluminum Round Grille (5-1/2 Installation is gravity drop• Slight variation in size and thickness may occur due to hand made nature of the product   Size Detail: ACHTEK ROUND-4” Edge: Beveled   Base Material:• Solid Cast Aluminum   Finish Detail:• Powder Coated-Matte Black• Powder Coated-Matte White   Mounting Easy to clean, vent cover may be re-painted with metal spray paint. HVAC Floor Vent Achtek 4 Inch Round Air Vent Grille - Solid Cast Aluminum Floor Register (Black) 4 Inch Round Grille Overall Face Plate size is 5-1/2 This size fits a standard duct opening diameter of 4 Achtek 4" Duct Opening Solid Cast Aluminum Round Grille ( 5-1/2" Round Overall) | Powder Coated Black - Without Holes for Floor · Achtek Air Supply Vent 6"x 9"... Made from solid sand-cast aluminum with a beefy 1/4-inch thick face plate, this thing is built like a tank. The 8x30 inch size fits standard duct openings...