4" X 8' - Round Duct Sheet Metal Pipe [4 pcs 2'] 12in diameter By simply measuring the width

By simply measuring the width or the length of the vent

+ Product Description Upgrade your HVAC system with our Premium Quality Straight Round Stack Boot

+ Product Details Perfect Fit & Easy Sizing - Designed for a 30" x 12" OR 12" x 30" duct opening (measured at the opening)

+ Product Details Size - 18"w X 16"h is the size for the duct opening measurement only

+ Product Details Size - 8"W X 4"H is (for duct opening measurement only)

4" X 8' - Round Duct Sheet Metal Pipe [4 pcs 2'] 12in diameter By simply measuring the width4" X 8' Round Duct Sheet Metal Pipe 4 PACK of 2' pipes 30 Gauge Galvanized Crimped End Connection 2 IN A PACK 4 Inch Diameter Pipe 10 Foot Length When Connected 30 Gauge Thick & Made of Thick & Durable Galvanized Sheet Metal Used For HVAC System Duct Work In Any Building or Home HIGH QUALITY High Quality Galvanized Sheet Metal with Crimped Ends (Snap Lock Design) For Easy Fitting and Secure Connection To Consecutive Duct Joints Made of Galvanized