I wasn't joking. The hole's not quite centred.Dan, that last post was very useful. Thanks. Do you happen to know if the Ther-Band tubes are eccentric as well?
I know you meant it as a joke, but I am making a visual chart, like eyeshot did above
I don't know about Thera-band tube though. I haven't looked closely at any, but I'm told they are made to close tolerances.
I have Theraband yellow, red, and green plus two sizes of no-name tan surgical rubber. None of them are perfectly concentric nor have perfect surfaces.