10 Pack 8" Round x 24" Long (Total 20 Feet) - 30-Gauge Round Duct Sheet Metal Pipe - Snap Lock Vent Pipe [10 Pieces, 2' Each] Wall Angle Register Boot the actual front end outer 4 X 12 Is CRFG2028 Width_14in

the actual front end outer dimensions are 8" in diameter

The edges are thoughtfully designed for mud and flange installation

+ Product Details Perfect Fit & Easy Sizing - Designed for a 18" x 16" OR 16" X 18" duct opening (measured at the opening)

85" width X 21

+ Product Details Size – 18"w X 36"h is the size for the duct opening measurement only

10 Pack 8" Round x 24" Long (Total 20 Feet) 30 Gauge Round Duct Sheet Metal Pipe Snap Lock Vent Pipe [10 Pieces, 2' Each] Wall Angle Register Boot the actual front end outer 4 X 12 Is CRFG2028 Width_14in the actual front end outer dimensions are 8" in diameter The edges are thoughtfully designed for mud and flange installation