MSL is a special unlock code.
With Z3X you are able to write that code into your phone and it can be unlocked.
Master Subsidy Lock (MSL) in the case of Samsung phones is the code that allows access to the engineering menu or service menu either to activate the UART - COM port or certain service modes on the phones so that it can carry out the security bypass process and then the sim unlock.
Z3X does not sell MSL codes.
In short, what the MSL does is reset the security of the phone in order to unlock it.
As soon as you enter this code through a box or software, you will only have to enter a generic code like 11111111 or 00000000 or 12345678
When you have MSL code and the MSL code process supported on your device:
1. connect your phone to the computer and start Samsung tool software.
2. click on the MSL unlock button
3. add the code and follow the instructions.