800 series simple, versatile, easy to operate, and easy to install. The 800 series register face is the same pristine white powder-coat we use on everything we make. There are 2 different damper configurations, and both of them work with our ceiling mounted T-bar step down diffusers, the 2000 series.

TRUaire™ Butterfly Damper with Installation Ring, 801 Model, 12 in Size, Steel, Non-Scuff Texture Brown Powder-Coated, 13-1/4 in OD Dia

• Controls air volume evenly over entire diffuser
• Removable adjustment handle, adjustment is made from the diffuser face
• Mounts directly into diffuser inlet

• Catalog https://assets.unilogcorp.com/267/ITEM/DOC/TRUaire_801_12_Catalog.pdf
• Full Engineering Drawing https://assets.unilogcorp.com/267/ITEM/DOC/TRUaire_801_12_Full_Engineering_Drawing.pdf