Round Stack Boot 10" X 3.25" X 5"- is Compatible with Duct 5" Compatible With Duct 8in Ideal for Walls & Ceilings:

Ideal for Walls & Ceilings: Designed for seamless installation in standard 24" X 6" duct openings

actual front end outer dimensions are approximately 20 5/8" width X 18 5/8" height

Overall Size: Measure the size of the opening

Ideal for Walls & Ceilings: Designed for seamless installation in standard 18" X 12" duct openings

The total outer size of this grille is the listed size plus 2 and 5/8"

Round Stack Boot 10" X 3.25" X 5"- is Compatible with Duct 5" Compatible With Duct 8in Ideal for Walls & Ceilings:+ Product Details Size The size of a galvanized sheet metal stack boot is 10" X 3. 25" X 5". It is compatible with duct 5". Design The stack boot at the bottom of the stack allows a transition from an ordinary large round or rectangular duct to a thin wall mounted duct. Applications The straight boot is used for a straight line transition going from round pipe or insulated flex duct to wall stack. Premium Quality Our straight round stack boot is made