Speedi-Products SM-RH3107 SB 3.25-Inch W by 10-Inch Length to 7-Inch Stack Range Hood Straight Boot Straight Boot style Galvanized 30 Gauge Sheet Metal 3 25-Inch x 10-Inch with crimped 7-Inch diameter pipe collar connection Seal joints with approved duct mastic sealants Consult your local building codes for approved installation practices