NORDFAB Reducer: 10 in x 4 in Duct Fitting Dia, 12 in Duct Fitting Lg - 40D560|8040025887 - Grainger
Round Duct Connector, Model RDC-8, 8 In Dia, For Models SP/CSP, Product # RDC-8 | Greenheck
AC INFINITY Duct Reducer, 8-Inch to 6-Inch Adapter Cone, Galvanized Steel - AC Infinity
AC INFINITY Duct Reducer, 8-Inch to 6-Inch Adapter Cone, Galvanized Steel - AC Infinity
Duct Outlet Short Duct Reducer HVAC, 9" x 8" - Walmart.com
Rheem Outlet Duct Adapter - GP Conservation
Snap-in duct adapter for 4" ducting
GE RAK6053 Duct Adapter for GE PTACs
Abs Duct Fan Connector Wall Range Hood Flange Adapter Kitchen Air Vent Exhaust Hood 100/120/150/200mm For Ventilation System - Pipe Fittings - AliExpress
Everbilt 4 in. Round to Oval Dryer Duct Adapter R2OHD - The Home Depot
Air Duct Adapter For 120mm Case Fan 4" and 5" Output – The House of Hydro
Snap-in duct adapter for 4" ducting
5" PVC Duct Flex Hose Adapter, 1033-FHA-05
L.B. White 16 in. Duct 2 to 1 Adapter Kit for Foreman 500 & 750 - John M. Ellsworth Co. Inc.
B3620 Duct Adapter
Air Duct Adapter For 120mm Case Fan 4" and 5" Output – The House of Hydro