Signed IPSW files can be restored via iTunes. Unsigned IPSWs cannot currently be restored via iTunes.
✓ | iOS 15.5 (19F77) | 16th May 2022 | 6.07 GB | iPhone14,6_15.5_19F77_Restore.ipsw |
✓ | iOS 15.4.1 (19E258) | 31st March 2022 | 6.04 GB | iPhone14,6_15.4.1_19E258_Restore.ipsw |
✗ | iOS 15.4 (19E241) | 14th March 2022 | 6.04 GB | iPhone14,6_15.4_19E241_Restore.ipsw |