Will Kenko extension tubes allow me to autofocus on a Canon 5D III with either of the new Zeiss Milvus Makro lenses?

Q. Will Kenko DG Canon AF Extension Tubes Set (36mm 20mm 12mm) extension tubes allow me to autofocus on a Canon 5D III with either of the new Zeiss Milvus Makro lenses?

A. I'm sorry to say that this would not provide AF as the Milvus lenses are manual focus only, none of the Zeiss SLR lenses have any AF motors or capabilities. The only Autofocus lenses Zeiss produce for stills cameras are the Batis and Touit ranges, and the Sony-branded lenses, that are designed for Compact System Cameras such as the Sony A7 models.
The Milvus lenses are basically the replacements for the older Classic Ziess lenses with the silver fronts, with improved optical design and weather resistance, and would work very well in macro with extension tubes due to the very long focus throw allowing precise manual focus, so are certainly a lens I'd recommend for macro work where maximum sharpness is required (particularly the 100mm) but there is no autofocus - for that you'd need to look to the Canon, Sigma or Tamron options.