Introduction
- 
                  
                  - 
            We can now see the bottom of the circuit board. It has a QR code with a serial number or MAC address. 
- 
            It also has a SIM card slot. 
 
- 
            
- 
                  
                  - 
            To remove the SIM card, use your nail to slide the metal bracket back 
- 
            Then, flip the bracket, and slide out the SIM card. 
 
-