EF Extension Tube Thinner than 12mm?

[JumboShrimp]

Anyone heard of these? I could make do with a manual focus one if I had to. I can find an old thread regarding this topic on DPReview but nothing available at that time. Has anyone made one of these in their basement "Dremel shop"?

 

[privatebydesign]

There used to be a three ring set on eBay that had an 8mm and two thicker ones.

 

[Don Haines]

There used to be a three ring set on eBay that had an 8mm and two thicker ones.

I think it was 8, 15, and 30....

 

[Don Haines]

There used to be a three ring set on eBay that had an 8mm and two thicker ones.

I think it was 8, 15, and 30....

http://www.bhphotovideo.com/c/product/888030-REG/vello_ext_cem_manual_extension_tube_set.html

 

[privatebydesign]

There used to be a three ring set on eBay that had an 8mm and two thicker ones.

I think it was 8, 15, and 30....

http://www.bhphotovideo.com/c/product/888030-REG/vello_ext_cem_manual_extension_tube_set.html

http://www.ebay.com/itm/AF-Confirm-Macro-Extension-Tube-for-CANON-EOS-EF-/370444048084?pt=LH_DefaultDomain_0&hash=item56402f96d4