One is set as the 'parent' SIM and incoming calls will only ring on that phone. If you're using the master and another call comes in, it can be configured to e

One is set as the 'parent' SIM and incoming calls will only ring on that phone. If you're using the master and another call comes in, it can be configured to either go straight to voicemail, or ring on the second phone. Quite convenient. This is available all over Asia - as usual, the Western countries seem to either be being held back by some regulation, or simply behind the times.