Offers
the ideal properties for increased efficiency in all heating and air
conditioning applications: 360 degree rotation, easy installation and
long term durability. Over-all diameter of 5-1/2" and is designed for
accepting all types of 4" flex duct. Incorporates a unique worm-drive
damper for increased operational efficiency. Just a quarter turn of the
center knob opens or closes the vent wings smoothly. In the fully open
position the vent wings are completely retracted allowing 100%
unrestricted air-flow. Available in dura-beige, walnut, black, white and
off-white.