Can I use the traffic of the main number when moving the secondary number?

Hello, under normal circumstances, the mobile secondary number cannot use the traffic of the main card, because it is only in the closed state, and the traffic is not superimposed. However, Mobile recently launched a service, Traffic Family Fun. Just turn on the traffic of the main card and add a secondary card. The secondary card can also use the traffic of the main card, and up to four numbers can be added. It should be noted that the main card charges 10 for each additional supplementary card. First edit the message KTGX and send it to 10086 to enable the family fun function, and then edit the message KTGX# membership number and send it to 10086. Now you can enjoy the discount of free function fee for the first two months, but I think this is chicken ribs and useless.