1. Place the Cat S53 on a clean flat surface with the display facing upwards.
2. Use your fingertip to open the SIM door and pull out the SIM tray.
3. Place the Nano SIM card into the SIM slot at the end of the SIM tray (SIM1) and then either the 2nd SIM or the SD card into the SIM2/SD card slot of the SIM Tray (SIM2).
4. Push the SIM tray inwards until it is in place and close the SIM door securely.
Note: The SIM tray will accommodate 2 x Nano SIM cards (Dual SIM, Dual Standby DSDS) or 1 Nano SIM and a SD card