D-Link DWR-966 User Manual page 19

PUK Verify: When you enter the PIN code incorrectly for three
consecutive times, your SIM card will be locked and you will need a
PUK code to unlock it. Please contact your service provider for the PUK
code. You have ten attempts to enter the PUK code to unlock your SIM
card. After ten failed attempts your SIM card will be permanently
blocked.
New PIN: Enter the new PIN code.
Confirm New PIN: Enter the new PIN code again.
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