OTA firmwares cannot be restored to. IPSW Downloads collects them for potential future use. They might also be useful if you're doing research.
| ✗ | Apple Watch Series 1 (42mm) | watchOS 4.0 (15R5365a) | August 22, 2017 | 1.1 GiB | a700bea6fbf3477d3dd3a2acdd72b2996c90c697.zip |
| ✗ | Apple Watch Series 1 (42mm) | watchOS 4.0 (15R5371a) | August 28, 2017 | 1.1 GiB | a0f1cfa08972b21d70c1dc664e841089de1892be.zip |
| ✗ | Apple Watch Series 1 (42mm) | watchOS 4.0 (15R372) | September 12, 2017 | 1.1 GiB | 894b23d8aac91dce6945ff5aa53975a58a2a137c.zip |
| ✗ | Apple Watch Series 1 (38mm) | watchOS 4.0 (15R5365a) | August 22, 2017 | 1.1 GiB | 9c42b41b015e3394d7c2ce0231450fa520e26758.zip |
| ✗ | Apple Watch Series 1 (38mm) | watchOS 4.0 (15R5371a) | August 28, 2017 | 1.1 GiB | 454bde80b4aec5e77da1dd00b7274f80b98abff7.zip |
| ✗ | Apple Watch Series 1 (38mm) | watchOS 4.0 (15R372) | September 12, 2017 | 1.1 GiB | 53abaea8f191fc294222dd8c264138b5c7295bf6.zip |
| ✗ | Apple Watch Series 2 (42mm) | watchOS 4.0 (15R372) | September 12, 2017 | 1.1 GiB | 1a0e3e9735f664775b34f1ef948050607e25dce0.zip |
| ✗ | Apple Watch Series 2 (42mm) | watchOS 4.0 (15R5365a) | August 22, 2017 | 1.1 GiB | 4b2eba0f23c55029e7195fea585958ae150408c1.zip |
| ✗ | Apple Watch Series 2 (42mm) | watchOS 4.0 (15R5371a) | August 28, 2017 | 1.1 GiB | d7950a0a2f6a0e0fa3bad9be28c2946543354b68.zip |
| ✗ | Apple Watch Series 2 (38mm) | watchOS 4.0 (15R5365a) | August 22, 2017 | 1.1 GiB | 87f71c8ea8c31ce3b63e8d5d8d8ae470acdf04ca.zip |
| ✗ | Apple Watch Series 2 (38mm) | watchOS 4.0 (15R5371a) | August 28, 2017 | 1.1 GiB | 9d0163e742f856aba2a1a6b3f16c1fd62a451df8.zip |
| ✗ | Apple Watch Series 2 (38mm) | watchOS 4.0 (15R372) | September 12, 2017 | 1.1 GiB | 7c9d2a641203ccab8c11daba73c3446c92abd408.zip |
| ✗ | Apple Watch (42mm) | watchOS 4.0 (15R5365a) | August 22, 2017 | 1.1 GiB | e8efda84b6a425012da945bd23bac1e40642d15d.zip |
| ✗ | Apple Watch (42mm) | watchOS 4.0 (15R5371a) | August 28, 2017 | 1.1 GiB | 4e2c0c8568a277634786dac1ac1a105df8466042.zip |
| ✗ | Apple Watch (42mm) | watchOS 4.0 (15R372) | September 12, 2017 | 1.1 GiB | 4b2a10e3de637c553f982604194988c90213478c.zip |
| ✗ | Apple Watch (38mm) | watchOS 4.0 (15R372) | September 12, 2017 | 1.1 GiB | d9b8cb294cd11eb5dfd104b0601d305bb095cea1.zip |
| ✗ | Apple Watch (38mm) | watchOS 4.0 (15R5365a) | August 22, 2017 | 1.0 GiB | 1100e6adca66cbe9c6e1ff3b42c54451be981fd5.zip |
| ✗ | Apple Watch (38mm) | watchOS 4.0 (15R5371a) | August 28, 2017 | 1.0 GiB | b7c330ac1460998bacce6047cd6595e8409caeca.zip |