Help from Nikon gurus??

[pphuang]

I needs some help indentifying this piece of equipment -

It looked interesting and was cheap, but now I'm trying to figure out what it is and how to use it. Is it an extension tube of some sort? There are no glass elements within the thing...

Thanks!!

 

[Gumby]

It certainly does look like an extension tube!

EDIT:

see http://www.mir.com.my/rb/photography/hardwares/classics/nikonf2/macro/index1a.htm

Here's what a guy on ebay says about the same item that he has for sale...
The Nikkor M extension tube was initially offered for the first Micro-Nikkor 55mm f/3.5 lens, and produced a macro ratio of 1:1. The rear mount of the extension tube is Non-AI, but will increase magnification on all Nikon lenses (Both AI & Non-AI).

 

[retro]

The Extension Tube "M" was for the first version of the
Micro-Nikkor 55mm f/3.5 which was a preset lens. Then Nikon
made an M2 tube for the 2nd major version of this lens which
had an auto diaphragm.

 

[pphuang]

Thanks for the info and link! This site is great!!