Vents are not STC'd or PMA'd.  Consult your local FAA authorities for proper field authorization options prior to install.
 
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.
THERMOMETER OPTION... CV-R1 (Thermal) variant.
 
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: 3mm Nitrile Rubber O-Rings that have more contact surface than avaliable options.
High Accuracy Thermometer: Commercial grade thermometer. ±1 degree of accuracy and no need to calibrate or be calibrated.  (See thermometer specifications for more details)
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), Nitrile Rubber O-Rings and Nylon (collet ring) which provides and lubricated glide around the tapered fingers on the eyeball socket.
 
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!, CV-R1 (Thermal) option shipment varies based on Thermometer 3rd party custom order."