This universal louver is made of highly durable plastic with precision construction. The louver is designed to fit any round opening measuring 3.75". The spring arms hold the louver in place and allow it to rotate 360 degrees within the opening. Adjustable vanes make sure you get air where you need it. When closed, the vanes offer 100% shut off of the airflow.
Outside Diameter: 4.5" (trim ring)
Mounting Hole Diameter: 3.75"
Attachment: Spring Retainer
Adjustable Direction: Yes
Adjustable Shut Off: Yes
Special Attribute: Fits Red Dot units R-9777, R-9727, R-6101, E-6100