Maxcom MM920 User Manual page 12

Be careful while using the memory card especially while
inserting and uninstalling the card. Some memory cards
must be formatted on a computer before the first use.
Regularly make backup copies of data stored on cards
used in other devices, if you use SD Cards. Misuse or
other factors might damage the card or make the card lose
its content.
Insert the battery so that the contacts +/- will
•
face upwards.
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