WARNING: This product can expose you to chemicals, which is known to the State of California to cause cancer and reproductive harm. For more information, go to www.P65Warnings.ca.gov.
Cummins Onan drawings and descriptions specify “to fit a specific diameter” which is the O.D. (outside diameter) of the tubing. For reference, the I.D. (internal diameter) of the tubing is 1/8 inch smaller (1/16 inch wall thickness tubing standard).