Verykool i605 - Manual (Page 55)

PUK (8 digits)
The PUK (Personal Unblocking Key) code is required to change
a blocked PIN code. Please contact your network operator for
the code.
Note: If you enter wrong PUK ten times, the SIM card gets
invalid. In that case, you have to consult with your network
operator for a new SIM card.
PIN2 (4 to 8 digits)
The PIN2 code, supplied with some SIM card, is used for some
functions, such as Call Cost, Fixed Dial and so on. Please
consult your network operator to confirm whether your SIM card
supports those services or not.
If you enter wrong PIN2 code for three times, the SIM card gets
locked and you will need PUK2 to unlock it.
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