double insulation symbol

 i got a desk lamp from ebay for 10$ like the one in the image link
below. the bulb is held up by two adjustable telescopic rods, exactly
the same type as you would find on the aerial of a FM radio. they are
metal.

i saw the double insulated symbol on the bottom, which go me thinking.
how did they get the wiring through these rods double insulated, they
are pretty thin. then i examined the rods. they had joints in them.
they werent even hollow! there was no wiring. they were the
conductors.

a quick check with the meter gave 20V AC.  thats how it was designed
to light the bulb .

my question is can you have the double insulated symbol on a product
with exposed 20V AC conductors?



http://www.flickr.com/photos/31506127@N03/3033028166

  On Sat, 11 Dec 2010, s wrote:


Because 20vac isn't particularly dangerous, the voltage is too low.

There's a transformer in the base that turns the 120volts from the wall
into the 20v the halogen bulb needs.

So surely the "double insulation" is about the ac line cord, and the
primary of the transformer.

     Michael

 s wrote:

Yep, all it needs to do is be double insulated between the metal and the mains.

Lots of stuff is.