Vent Systems 8" to 6" Inch Duct Reducer Adapter Connector Fitting Pipe Increaser Reducer Cone for HVAC Ventilation Systems, ABS Plastic PVC Pipe 200 to 150 mm - Amazon.com
8" x 6" Schedule 40 Reducing Coupling 429-585
8" x 6" Sch 40 PVC Reducer Bushing Flush Style - Spig x Soc 437-585
Vent Systems 8" to 6" Inch Duct Reducer Adapter Connector Fitting Pipe Increaser Reducer Cone for HVAC Ventilation Systems, ABS Plastic PVC Pipe 200 to 150 mm - Amazon.com
8" x 6" PVC Duct Rolled Reducer Coupling, 1034-RCR-0806
NDS PVC S&D Increaser/Reducer Coupling, 4 in. Hub X 6 in. Hub 6P07 - The Home Depot
8 x 6" PVC Duct Reducer Coupling 1034-RC-0806
8" x 6" Schedule 40 PVC Reducing Coupling, slip x slip 429-585
NDS® 8" x 6" Hub PVC Reducer Coupling Sewer & Drain at Menards®
IMPERIAL 10-in x 8-in Galvanized Steel Duct Reducer in the Duct Transitions & Connectors department at Lowes.com
Charlotte Pipe 6-in x 8-in PVC DWV Reducing Bushing in the PVC DWV Pipe & Fittings department at Lowes.com
8 to 6 Inch Duct Reducer, Hon&Guan Duct Adapter 8 to 6 PVC Reducer, Duct Increaser/Reducer for Grow Tent HVAC Ventilation System. (200 to 150mm) - Amazon.com