Device guides for

Samsung Galaxy S21 Ultra 5G

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List of screen icons Use voice control Choose a network Choose network mode

Getting started

Basic functions

Calls and contacts

Messages and email

Manage apps and data

Camera

Internet and data

Global services

Troubleshooting

Specifications

Choose dual SIM settings

When you insert two SIMs into your mobile phone, you can make calls and send and receive messages from both SIMs. You can also select a default SIM for mobile data usage.