It's esentially the same thing... a 6" diameter sauna tube. The wall thickness is no more than 1/8", or it would've been a nightmare to try and cut it.
Intersting idea you have, a Tau symbol die rolling tray. I've made die rolling trays in the past, but never a circular one. I'll post a picture of mine later as security protocols on my work computer prevent me from seeing/accessing photobucket.
Here's the die rolling tray that I mentioned earlier. I have sections for storing my dice, round counter ( the uber sized die ) and scatter dice.
The bottom is a piece of hardboard, the sides are made from foamcore that's been topped with thin cereal box card... I also covered the outside with the thin card as well, for added protection.