Panasonic Toughbook CF-31AAA7J1M Reference Manual page 88

Wireless WAN
To insert a SIM card
1
Turn off the computer.
2
Open the cover.
3
Insert the SIM card into the SIM card slot with the contact
side facing downward and with the cut corner oriented as
shown in the illustration.
CAUTION
Do not insert the SIM card upside down.
4
Close the cover.
If the cover is not closed, the SIM card may jump out when the computer falls.
88
SIM Card
Contact