This firmware is not signed. This means you cannot restore to it in iTunes.
| Release Date | 19 December 2023 |
| Upload Date | 16 December 2023 |
| File Name | iPhone13,4_17.2.1_21C66_Restore.ipsw |
| File Size | 7.24 GB |
| SHA256sum | e54c05c5a383ba9845713b057117e56d576fca3601d892f1f36ef635b050731e |
| MD5sum | accd4718bc2111e9a0cd9d5b86cb0c03 |
| SHA1sum | 2a31d3bbab2031bcd7b0cd6620b8874bf0e3d2cf |
| Identifier | iPhone13,4 |
cd ~/Downloads.idevicerestore -e iPhone13,4_17.2.1_21C66_Restore.ipsw and press Enter.