This firmware is not signed. This means you cannot restore to it in iTunes.
| Release Date | 25 October 2021 |
| Upload Date | 15 October 2021 |
| File Name | iPhone13,4_15.1_19B74_Restore.ipsw |
| File Size | 6.17 GB |
| SHA256sum | 4be85b0647734c3dbf7d4eba63a4726aac6cfd4075526b1a3ae871b0d06cff02 |
| MD5sum | 8d4f41e2e152d54b62a6123985ee4616 |
| SHA1sum | 29f0436d777732c2d91fed60c8ac972674520dd7 |
| Identifier | iPhone13,4 |
cd ~/Downloads.idevicerestore -e iPhone13,4_15.1_19B74_Restore.ipsw and press Enter.