Huawei E397 4G LTE Mobile Internet Key Quick Start Manual page 5

Inserting the microSD Card
Insert the microSD card into the USB Stick, as shown in the following figure.
Note:

The microSD card is an optional accessory that can be purchased from
TELUS.

Do not remove the microSD or SIM card while the internet key is connected to
your computer. Otherwise, the cards or internet key may be damaged.
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