As Chris says, it's difficult to tell the 2 spindle from the 2.5; but not impossible. I can usually tell when it's a 2.5. Look at the diameter of the spindle in relation to the diameter of the arm wand. In photos, the 2 spindle usually looks to be about the same or slightly larger in diameter as the original aluminum arm wand or smaller than the magnesium. The 2.5 spindle clearly looks wider than the original wand and about the same or slightly larger than the mag. Based on the pic in the ebay link, I believe Manitunc has a 2.
BTW, there seem to be two different magnesium wands. Mine (I bought it years ago right after Bruce started making them) does not have the "step" in it's diameter toward the rear of the arm.
BTW, there seem to be two different magnesium wands. Mine (I bought it years ago right after Bruce started making them) does not have the "step" in it's diameter toward the rear of the arm.