NOTE: The images shown are for reference only, the actual product may differ.Therefore please always read the description or read on the corresponding catalog page.
Set of 2, approx. 1/2" (12.7mm) longText excerpt from the catalog:
Adapts 1/2-13 UNC thread to 3/8-16 UNC, for example to use 1999-up breather bolts on earlier style cylinder heads.