AllFuelHST Stove Pipe Adapter for 6"Chimney Pipe - ComfortBilt
10 Inch to 6 Inch HVAC Duct Reducer & Increaser - 26 Gauge Galvanized Sheet Metal Ducting Connector for Airflow, Heating, Cooling, & Air Ventilation System Extra Strength and Fittings - Ducting Components - Amazon.com
5in. to 6in. Single Wall Black Stove Pipe Increaser/Reducer - Amazon.com
Chimney Pipe Adapter for Selkirk Metalbestos Class A Insulated Pipe
IMPERIAL 6-in x 4-in Galvanized Steel Duct Reducer in the Duct Transitions & Connectors department at Lowes.com
6" to 4" Reducer Adapter for Ventis - Tiny Wood Stove
Imperial Black Matt Stove Pipe Reducer/Increaser – US Fireplace Store
Snap-Lock Black Steel Stovepipe 8-Inch Male to 6-Inch Female Reducer
DuraVent PelletVent 4 in. x 6 in. Double-Wall Chimney Pipe Adapter in Black 4PVL-X6 - The Home Depot
Steel, For 12 in Dia, Duct Reducer - 6EKL2|GRR12P6PGA26 - Grainger
Increasers Reducers & Adapters - Single & Double-wall Black Pipe - Products - 6 24 Gauge Black
5"-6" Stove pipe adapter - Four Dog Stove Co.
Master Flow 6 in. to 4 in. Round Reducer R6X4 - The Home Depot
Plastic 6-Inch to 5-Inch, 4-Inch Converter Cone Reducer for flexible/PVC Pipe | eBay
IMPERIAL 6-in x 4-in Galvanized Steel Duct Reducer in the Duct Transitions & Connectors department at Lowes.com
Imperial BM0074 Stove Pipe Reducer, 6 X 4 in, Small End Crimped, 24 ga