When I use the 1996 tube stock I have noticed some trains have more modern looking side door panels inside where the button is positioned at the bottom of the metal button panel as opposed to the top and has a square key on the white panel, as opposed to just being on the bottom gray panels. I would assume this is the 05 variant. However I have been on other 1996 tube stock That seem to look exactly like the original 1996 stock with the same side door panels but the have orange dot matrix so I would assume that that is actually the 05 variant. But that means that their must be another variant apart from the 05 stock variant.