A device that adds 3G or 4G (LTE) cellular connectivity ... for desktop computers, the modem may also be available on a PCI or PCI Express (PCIe) card that plugs into an empty slot on the motherboard.

Reliable LTE modem featuring fast speeds, carrier compatibility, and versatile connectivity-perfect for primary or failover ...

See PCI and PCI Express. Cellular wireless adapters, also called "cellular modems," "air cards," "broadband adapters" or "broadband cards," deliver the same 3G, 4G and 5G wireless service that ...