Out with the OLD in with the NEW.  "CV-R1" is my solution to the old TIN CAN CESSNA VENTS. 
 
33% INCREASED AIRFLOW... over the legacy vents... see video for testing results.
 
"Full disclosure, I came across this particular eyeball design concept while researching eyeball vents. This particular collet ring design was originally developed by Rossi Engineering located in Lexington, Kentucky for an experimental project he was working on. The design was simple yet very effective allowing for variable flow control, direction flow, secure position of the eyeball and ability to be easily 3D printed which was key. Added bonus is that it did not require any machined aluminum parts which helps to keep the cost down." 
 
Why design a replacement vent?  The original vents are hard to find, poor fit, poor airflow and most of all costly. The only other suitable alternative is put out by a major vendor which are very expensive, not modular and could use improvements. 
 
CV-R1 design goals and solutions: 
Better Fit: TPU compression O-ring that has more contact surface than traditional O-rings.
Modular Design: Separate barrel, manifold, eyeball and collet ring allowing for best build orientation for 3D printing. Also provides the flexibility for design refinements and new options without total kit replacement. Ultimately saving money.
Improved Airflow: Maximize airflow by inserting a manifold between the barrel and eyeball. Manifold would promote a laminar transition of 1.6 : 1 increasing outlet velocity 33%. See test video showing results.
Variable Airflow: Eyeball with internal curved path for control of airflow and direction (Direct contact). 360 degree eyeball rotation necessary for blocking airflow with flat side for quick reference. Orientation mark for max airflow. 
Heat Resistant Materials: PETG (barrel, manifold and eyeball), TPU (compression o-rings) and Nylon (collet ring) which provides and lubricated glide around the tapered fingers on the eyeball socket.
Color Options: Ability to custom order colors and coordinate as desired. Options are: Black, White, Gray. Other colors may be available upon special request.
 
Which Cessna's does it fit?
Fits Cessna's with the "Tin-Can" type air vents manufactured before 1981. Always verify your measurements to those provided prior to ordering.
 
"As orders are 3D printed and assembled upon purchase, please allow up to two weeks for shipment!"