Standard/Mini-SIM (15 x 25mm) GSM card of your operator with an unlocked PIN.
CheckFox is supporting 3G/Edge GSM at these frequencies. LTE is not supported.
800/850/900/1900/2100 MHz @UMTS. 850/900/1800/1900MHz @GSM. It is using Quectel UG96 modem.
The data transferred via GSM is one hundred bytes per measurement plus overhead, so you don’t need huge data plans. If you do 1000 measurements per month you need one MByte data plan.
Switch off the device.
Unscrew the 6 screws from the back. Place Checkfox display facing up. Carefully open the upper part from left and turn it over 180 degrees keeping keyboard wires connected.
Push and open/lift the SIM card holder from right.
Open it fully.
Insert the SIM card with PIN unlocked
Close the holder, push and slide back to the right.
Close the lid.
Screw back the screws.
If needed the IMEI can be found in Service Menu - About.
Change the APN connectivity setting in Service Menu - Settings