This is iCloud unlocking by hardware method
1. If your device is a cellular version (4g/LTE) You need to cut off the gsm baseband to make it wifi version only.
2. Dismantle the Nand IC and use box to edit write new Full set serial by (Navi pro, iP-box, WL or others)
3. Restore your iDevice & activate it.
4. Enjoy your iDevice