> ## Documentation Index
> Fetch the complete documentation index at: https://docs.hologram.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Network selection

Hologram SIMs are provisioned for permanent roaming and hold credentials for **550+ networks** across **190+ countries** ([read more](/guides/get-started/country-and-network-coverage)). Modem firmware scans and selects networks based on supported bands, signal conditions, and device logic.

Traditionally, a modem connects to the strongest viable network. Availability varies by device bands, geography, tower traffic, and firmware. For firmware-specific behavior, consult your device manufacturer's documentation.

Hologram Hyper SIMs with Outage Protection add resiliency by providing two independent connectivity profiles spanning 330+ global networks each. During an outage, your SIM can transition cores to minimize downtime. [Learn more about Outage Protection](/guides/sims/outage-protection).

## Can I customize network selection using a Hologram SIM?

Coverage on a SIM can be limited to specific networks via custom data plans and the profiles installed on your SIM. With Outage Protection enabled, the SIM can switch to a backup profile if the primary profile loses connectivity extending the coverage available to your SIM. With this combination you can prefer access to a Tier-1 high-performance network on one profile, while still having global coverage as a backup on the other profile.

Hologram recommends steering connectivity to specific networks on your device, and using Forbidden Public Land Mobile Network (FPLMN) lists to avoid networks, and Operator Preferred Public Land Mobile Network (OPLMN) lists to prefer networks, updated on your SIM via AT terminal commands.