I think that they are universal, all the ones I have are 100-240, The only thing that changes is the mains AC plug, which is also a separate part from the housing.
There should be three or four version of this power supply:
-one has a huge DC plug (with 24W written on it), they don't have the capacitor issue (yet) (I own one and it is the only one that has never been opened), the model number is M5652 (APS-46E) on the label, it outputs 7.5V, 3A
-the more common (and older) one, with a small DC plug, model M5140 (APS-20E), all of them suffer from leaky ELNAs. It outputs 7.5V, 2A, I own 5 of these and repaired a lot of them.
-another one that looks the same as the APS-20E, doesn't have ELNA capacitors but there are two "box" (GameGear) style one on the vertical controller board that usually fail, I don't have one, so I can't give you all the specs
There should be another model, maybe used for the QuickTake or other accessories, it looks the same as the powerbooks ones but I think it has a different circuit inside, just seen this model in photos
There should be three or four version of this power supply:
-one has a huge DC plug (with 24W written on it), they don't have the capacitor issue (yet) (I own one and it is the only one that has never been opened), the model number is M5652 (APS-46E) on the label, it outputs 7.5V, 3A
-the more common (and older) one, with a small DC plug, model M5140 (APS-20E), all of them suffer from leaky ELNAs. It outputs 7.5V, 2A, I own 5 of these and repaired a lot of them.
-another one that looks the same as the APS-20E, doesn't have ELNA capacitors but there are two "box" (GameGear) style one on the vertical controller board that usually fail, I don't have one, so I can't give you all the specs
There should be another model, maybe used for the QuickTake or other accessories, it looks the same as the powerbooks ones but I think it has a different circuit inside, just seen this model in photos