Unfortunately, there is a 'but': The magnet for the standby function is too strong or sitting in the wrong place. If I Ho-Ver turn the cover and the Kindle holding the bottom right (as shown in the second picture), the Kindle goes into standby. I have therefore resorted to glue a small Silikonböppel on the front, which provides two additional millimeter distance of the cover to the magnetic sensor. Is not very pretty, but it works.
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Addendum: I get a new shell, in which the problem no longer exists. Therefore now 5 star.