The device is useful for a naked Z1 Compact. There has then indeed a shaky state. But it works the charging function. With a Bumper without cover both bets are useless. These are too narrow. They also differ in legal and left only two small edges. With a Bumper with a lid, it is not useful. You have to leave open the lid and depend. A slightly wider shaft would be helpful here. Therefore, no more than three stars.
