Verykool i604 - Manual (Page 56)

1. Enter the correct PUK2 to unlock PIN2, and then enter the
new PIN2 and press OK.
2. If you are prompted to enter the new PIN2 again, enter it and
press OK.
PUK2 (8 digits)
The PUK2 code, supplied with some SIM card, is required to
change a blocked PIN2 code. It may be supplied with the SIM
card. If not, contact your network operator.
Note: If you enter wrong PUK2 ten times, the SIM card will get
invalid. In that case, you have to consult your network operator
for a new SIM card.
Barring Code
To activate call barring, you need a Barring Code. You can obtain
the password from your service provider.
49