Huawei Mate 8 - Manual (Page 4)

Getting started
Follow the instructions in the following figures to set up your phone.
Do not insert or remove a SIM card while your phone is on.
Please exercise caution when using the SIM ejector pin to avoid
hurting your fingers or damaging your phone. Store your pin in
a safe place out of the reach of children to prevent them from
swallowing it or injuring themselves by accident.
Caution
Insert the SIM card into the correct card slot to ensure that it can
be recognized by the phone. NXT-L09 NXT-L29
OR