How much traffic the secondary card uses will inform the primary card.

The secondary card starts sending short messages to inform the primary card with half the traffic. The main card opens the secondary card, and when the traffic of the secondary card runs out of half, it starts to send SMS reminders, and both the main card and the secondary card will receive this SMS reminder at the same time. Roughly speaking, this month's traffic has already used 10GB. When it exceeds 20GB, the data traffic will be reduced first, and the speed limit will be reduced to 1mbps, which may greatly reduce the user experience. Some high-traffic apps may not be able to surf the Internet normally, so please plan your traffic usage.