Wayne, are you sure its a one piece hex and not rounded tube in the catalog? I must have missed that.
Sanityclause,it`s hard to tell by the catalog pic even with a magnifying glass but it is a one piece 12" for sure.It doesn`t say if it is a knobby attachment which would lead me to believe it`s round.But it also says there are(2) knobby attachment units-one is a utility unit to handle 3/8"round rods and the other with a larger trench to handle hex,so there`s no clear cut answer here.Interesting stuff and if you get to the bottom of this please let us know.
Wayne