fat tony
CGN Ultra frequent flyer
I recall these fun little puppies from (guess where), the brown glossy painted vaguely - dynamite stick appearing 'blast simulators' for want of a better term, with the black printing / warnings on them, I once took one apart
, I found that mainly the thing was made of cardboard, the container with the pyrotechnic composition in there was translucent plastic, about as big around as my little finger and filled with a greyish powder(flash powder/EC blank powder?
) - were they American, British or Canadian in origin? 
EDIT: looks like I might have answered my own question:
http://www.hfmgroup.com/professionalsupplies/thunderflashes.html

EDIT: looks like I might have answered my own question:
http://www.hfmgroup.com/professionalsupplies/thunderflashes.html