This firmware is not signed. This means you cannot restore to it in iTunes.
| Release Date | 24 September 2019 |
| Upload Date | 17 September 2019 |
| File Name | iPhone_4.0_64bit_13.1_17A844_Restore.ipsw |
| File Size | 3.37 GB |
| SHA256sum | 0fef7700ad5d65ba10e98e8b134793f666250b9009b9d5453e751654c2de75f5 |
| MD5sum | 700925448f73e65d8ceb980faaa2cdfc |
| SHA1sum | 8aec01fefef418994c879c7f3ff20e6b2e8eff9e |
| Identifier | iPhone8,4 |
cd ~/Downloads.idevicerestore -e iPhone_4.0_64bit_13.1_17A844_Restore.ipsw and press Enter.