Hi guys,
The tube is made out of vinylester, and is kinda oval.
It is 6.5 x 7.5 inches inside at the mouth.
The top of the mouth is aluminum that is glassed in and faired. It is about 7` 3" long
The whole thing weighs aprox 2lbs and as mike said is very breakable. My kite came with 2 bellybuttons but I think I need to add one more.