[HomeBrew] Help identifying a component

[pete wokoun, sr.]

Hi,

  I removed these little thingys from a military power supply I stripped 
down and have no idea what they are.  No identifying marks, they are about 
3/16 inch in diameter and 5/8 inch overall.  They have two isolated 
terminals above the mounting thread.  The thread is a 4-40.  Ohmmeter shows 
no continuity anywhere.  Put up to 50 volts across the isolated terminals 
and from each terminal to the mounting stud and no current flow with any 
polarity.  You can view them at:

http://www.kodakgallery.com/BrowsePhotos.jsp?&collid=135946563208&page=1&upload_count=4

I uploaded them as a guest so have no idea how long they'll stay there.  If 
you click on a particular picture you can get it enlarged.

I'm hoping someone will recognize them and say it's just a throbbledegunk or 
whatever.

Thanks!

Pete