i couldn't find you a pix but this is from the RUUD lighting site;
New Airtight Recessed Cans
Recessed downlights can create open airways between temperature-controlled rooms and their uncontrolled attic or plenum spaces. Our new Insulated Ceiling Air Tight Recessed Downlights (ICAT Series) minimize air infiltration and leakage. This is especially important in states where codes require airtight recessed fixtures. Our ICAT Series is offered in three popular models, 4" Incandescent (R4ICAT), 6" Incandescent (R7ICAT) and 6" Fluorescent with 18W lamp (R7FICAT18). For other projects where direct contact with insulated ceiling materials may occur, use the 4" Low Voltage Incandescent (R4LICAT), 6" Economy Incandescent (R7EIC) or 6" Incandescent for remodel projects (R7RIC). If you choose to use another housing, be sure the insulation is at least 3" away from housing and junction box.
all they have different is a gasket around the trim hole, big !*&%$ deal! They are buried in insulation as it is. I also had an architect spec out vapor barior boxes once, they come with a little plastic flap. Being that i live up in the great white north i get this all the time, people retire here, build a post & beam streesskin home, insulated to R-346 to the point where the piolets go out in the stove and furnace due to lack of O2, and mama always has a headache...he**, a fart sticks around 3 days....but they save a whole 20% off normal construction fuel costs by god!
A few homes that i did like this came to the relization that they had a problem, so then they called in some NEW engineers that addressed the air exchanging, more ductwork etc...
There seems to be this manufacturing hype that drives this 'energy code' thing.....
Let 'em all go cut wood I say, maybe then they would'nt grow A***s the shapes of thier chairs an' stumble around for thier nitro everytime the doorbell rings