This item is a 9" EzySlide Round Damper manufactured by Arzel Zoning.
EzySlide dampers are the primary damper design for Arzel Zoning systems. 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. They are installed by cutting a hole into a metal duct, inserting the damper, then securing with screws. The insertable installation makes them retrofit-friendly, and the motorless design eliminates the need for motors or gears, so they are extremely reliable. Dampers are actuated by low pressure air supplied by a medical-grade pump inside the panel. Available in 70 stock sizes, with sleeved dampers available for non-metal ductwork. Compatible with any Arzel Zoning panel.