Is the mobile voice doubling package free?

The mobile voice doubling package is not free. According to the official website of the mobile company, the mobile voice double package is a value-added service launched by China Mobile. It requires a certain fee to increase the user's usage threshold and screen out users who really need this service, which can increase the operator's revenue sources. . The mobile voice doubling package can double the user's voice duration, allowing users to enjoy more benefits in terms of call duration.