Cap is marked: Never Open Hot Check Level in Bottle TVS RC33 15lb Closed System Align Arrow & Vent Tube. Center label states Pressurized System. ACDelco RC81 15# Stamped RC33 by Delco as a Superseded Part Number Stamped Aluminum Cap Measures 2-3/16 Diameter by 1 Inch Height This ACDelco GM Original Equipment radiator cap is a must-have for any car or truck owner. The SKU number XAD:RC81 ensures that you receive the correct item for your needs. This cap is designed for use with engine cooling components and is a genuine GM product. It is easy to install and will provide a long-lasting seal for your radiator. Don't let a faulty cap cause engine overheating - replace it with this high-quality ACDelco cap today.
