Revolutionary Split-Boot design puts an end to manifold vacuum leaks and installation headaches. I.D. of small end is 1 1/4". I.D. of large end is 1 1/2".
WARNING: This product can expose you to chemicals which are known to the State of California to cause cancer and reproductive harm. For more information, go to www.P65Warnings.ca.gov. All parts legal for use on pre-pollution controlled vehicles only.