Drill rod was used for the MT0 arbor. T6061 Aluminum for the barrels.
The first barrel has a hex for what I think is a 10mm metric die. Not sure where I got that one!
The other end of the first barrel has a 5/8" hex die for dies such as Hanson.
The second barrel has only one end prepared for a die. That is for the 3/4" round die.
Pictures and prints below: