The FAMCO motorized HVAC dampers are available in spring return, multi blade and power open power close models. The ADO and ADC motorized dampers have a 24 volt or 120 volt motor option. End switches are also available with these models. End switches allow another appliance to be operated when the damper has reached its full power position (either open or closed). The floating motor mount design assures proper alignment of motor, shaft and damper to prevent binding, while the clutch/coupler reduces the number of moving parts for greater service life. All ADC and ADO units without the end switch come with a flow control adjustment so that the damper blade can be blocked from opening or closing 100%. Please keep in mind that the end switch will not work if the flow control adjustment is preventing the damper from reaching its full powered position. Our Multi-Blade Dampers are used for zone control, air inlet and exhaust applications. This damper is built with aluminum opposed blades and provides minimum weight with maximum strength. This features a high torque 24 or 120 volt motor, with power open and spring close blades. The parallel blade design provides smooth operation and efficient low leak sealing. The Power Open Power Close Dampers come with a high torque 24 volt motor that operates in both directions. This damper features an easy wire terminal and 3 wires to integrate with two or three zone systems and a rotation switch to set at “normally open” or “normally closed”.