One of Rossi’s greatest innovations is eliminating the old style ‘wingnut’ as the locking mechanism used in manual air flow regulators. Wingnut-style regulators (damper handles) have 3 problems. (1) Tiny vibrations in the duct cause the wingnut to come loose over time. (2) This creates rattling sounds in the duct and (3) disrupts the air balance in the building. Metal wingnuts can even rust shut making it impossible to adjust the position of the regulator handle. For these reasons, every Rossi regulator eliminates the wingnut as a locking mechanism. The Everlock & Megalock models use our patented positive-locking mechanism with pre-designed positions which allow you to set it and forget it. Our Twistlock model allows for an infinite range of balancing control with our superior-grip orange knob.


Positive-Locking Damper Handle for 3/8″ shaft available with a 2″ or 1.5″ standoff bracket.



Positive-Locking Damper Handle for 1/2″ shaft for rectangular blades and larger applications (18″ diameter blades and larger)



Hand Twist Locking Damper Handle for 3/8″ shaft available with 2″ or 1.5″ standoff bracket.


Twistlock FlatTM

Hand twist Locking Damper Handle for 3/8″ shaft.  Sits flat against duct when no standoff is needed.


Customer Reviews

Get Your Free Samples