This item is a 18" Commercial Round Damper manufactured by Arzel Zoning.
Arzel Commercial Round Dampers are heavy-duty sleeved dampers for use in commercial zoning projects. These dampers are connected to a zoning control panel with pneumatic tubing, and they open and close by getting pressure or vacuum from the panel pump. Dual actuators for heavy-duty commercial applications. Gasketed internal blade provides positive seal. Shipped preassembled in spiral duct. Compatible with any Arzel Zoning panel.