Most Bose docking stations with the 30 pin connection (for
older style iPhones e.g 3 & 4) will work with either the i-SYNC or the
i-DOCK. The only Bose that isn’t compatible is the very original Bose Series 1
If you have a Bose Series 1 SoundDock you need the BS-1 which has been designed specifically for this docking station, since it runs from a different charge output to all subsequent models. For later models, either the i-SYNC or i-DOCK will work.
If you’re not sure which Bose you have, you can tell by
testing an iPhone 4 in it. If the Bose CAN charge the phone whilst docked, it
is a later model and you can use either the i-SYNC or i-DOCK.
If your Bose CAN’T provide a charge to the iPhone (it will say ‘charging not supported’) you need the BS-1. This is the only 30pin receiver that will work.
If you don't have an iPhone to test, please purchase one of
the receivers and in the event that it is the wrong receiver for your dock, you
can return it for a refund and purchase the correct receiver. Unfortunately it
is impossible for us to tell which Bose you have from the serial number.