I did not constantly having to press the off / power button an envelope with the Wake / Sleep function to what would have been clear to me too much trouble in the long run.
After a very fast delivery I reinbekommen my eReader immediately without problems in the shell and have of course tried the Sleep / Wake function and immediately after the Istallation the device and what can I say, it worked and also the magnetic closure holds bombproof.
So if you want not spend a lot of money for a protective shell of his eReaders, is well advised with this case and will not be disappointed :)