Usage expectations (rule of thumb)

• Light use (email, browsing, social) over a month is typically around 1GB.
• Video streaming uses significantly more data and can consume multiple GB quickly.
• Consider setting streaming quality to SD (480p or less).

Settings that help

• Apple: Low Data Mode
• Android: Data Saver Mode

Avoid unexpected costs on your primary SIM

Disable Data Roaming on your primary SIM so it does not connect to networks you do not intend to use.

Source: https://support.limitflex.com/en/articles/9769637-tips-tricks