Duct Outlet 8 x 8 Ceiling Box, w/ 6 Round Collar - Connects Register Vent and Diffuser HVAC

4" High x 3" High Collar 26 Gauge Galvanized Steel, Single Wall with No Insulation Built with standard plaster ground flange all the way around the square portion. Connects a 6" Round Duct to a 8" x 8" Diffuser or Register Vent. The ceiling box is nailed into the attic rafters and plastered or dry walled around the flange called plaster ground.