Radium Engineering Catch Can O-Ring Service Kit is compatible with Radium Engineering standard catch cans. It is NOT compatible with the Radium Engineering AOS-R or large Competition Catch Cans. THIS KIT INCLUDES:-2x Small dipstick O-rings (approx. 0.27" diameter, green)-2x Catch can canister O-rings (approx. 2.1" diameter, black)Lubricate all o-rings during installation.