![Winchester 20.5-in x 17.5-in x 28-in Return Air Box Assembly Duct Plenum in the Duct Parts department at Lowes.com Winchester 20.5-in x 17.5-in x 28-in Return Air Box Assembly Duct Plenum in the Duct Parts department at Lowes.com](https://mobileimages.lowes.com/productimages/8cabf13a-9d8c-461a-b307-fde9364db370/03154885.jpg?size=xl)
Winchester 20.5-in x 17.5-in x 28-in Return Air Box Assembly Duct Plenum in the Duct Parts department at Lowes.com
![HVAC Plenum Ceiling Box 16X16X16 (16"X16" Square to 16" Round) with Drywall Flange - Connects to Vent Register Diffuser, Galvanized Steel Metal C-Box Duct, Airflow Conditioning Ceiling Registers - Heating Vents - HVAC Plenum Ceiling Box 16X16X16 (16"X16" Square to 16" Round) with Drywall Flange - Connects to Vent Register Diffuser, Galvanized Steel Metal C-Box Duct, Airflow Conditioning Ceiling Registers - Heating Vents -](https://m.media-amazon.com/images/I/51h-+AIptuL.jpg)
HVAC Plenum Ceiling Box 16X16X16 (16"X16" Square to 16" Round) with Drywall Flange - Connects to Vent Register Diffuser, Galvanized Steel Metal C-Box Duct, Airflow Conditioning Ceiling Registers - Heating Vents -
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