In my older ThinkPad, the SIM was a slot behind the battery. In a later model, it's a tray that has to be opened with a paperclip next to the card reader. The m

In my older ThinkPad, the SIM was a slot behind the battery. In a later model, it's a tray that has to be opened with a paperclip next to the card reader. The modem itself is a mini PCIe card like they're used for some laptop SSDs and antennas are in the screen like wifi antennas.