Engine Coolant Reservoir Cap Manufactured to meet all OEM specifications. Designed to be easy to install and remove. Manufactured from high quality components with proper relief and vacuum valves. Quality tested to stand up to even the most demanding automotive cooling systems. Coolant Recovery System: Open, Closed System Lever Type: Standard Pressure Rating: 18 PSI Prop 65: WARNING: Cancer and Reproductive Harm - www.p65WARNINGs.ca.gov SAE Pressure Range: 16-20 PSI Valve OD: 1.29 in Width: 1.94 in Attachment Type: Threaded Color: Black Material: Plastic, Rubber Pressure Release Lever: No Pressurized: Yes Vented: Yes