To elaborate a bit on what's already been said...
All Magic Bands (both the older 1.0 and the current 2.0 versions) use the same technology. There are two RFID chips in each band. One needs a battery to power it (the "active" chip), the other does not (the "passive" chip).
Currently, there are only two things the active chip does; automatic ride photos, and special experiences such as having your name show up at the end of IASW. For everything else, where you tap the bands to a Mickey Head, the passive chip is used.
Unless you specifically care about the active functions, any old magic bands you have will work just fine.
Steve