Can you use the Kindle (AC) power to usb adapter be used to charge other electronics?

More specifically a mp3 Sansa clip + which comes with no power adapter and charges by USB? Does it come out at a specific current that only works on certain items? There are adapter that are advertised as specifically for it. There also adapters that are general purpose. The adapter says Output 5 volts then (straight line over three dots) to .85A and Input:100-240V-.15A 50/60 hertz. Its white and says amazon on it.