The iPhone Duo was introduced in 2026, shipped in 256 GB, 512 GB, 1 TB and 2 TB configurations, was offered in Night Sky and Star White.
Device facts (year, capacities, colours) from Apple Support. Capacities and colours can vary by model and region.
iOS 27.1
- Identifier
- iPhone19,4
- Model Number
- A3447, A3719, A3721, A3720
- BuildID
- 24A94425
- Release Date
- October 22, 2026
- Filesize
- 11.85 GB
- Filename
- iPhone19,4_27.1_24A94425_Restore.ipsw
- SHA256
- 58fbfda85615e90221136d55288f64c9f41386510f8cd77feb8c9d20cc0a782e
- SHA1
- 19f1bafde7dc4cba523a146a16213464aaf3bf90
- MD5
- 269b204e32ee3eed9a3582f1f211aa70
- Download URL
-
This page covers everything Apple has published for the iPhone Duo (device identifier iPhone19,4).
Apple sells that device under several model numbers — A3447, A3719, A3721 and A3720 — which cover its regional and connectivity variants, and the firmware on this page works on all of them.
Before downloading, verify this is the correct device model:
- Go to Settings → General → About on your device
- Check that Model Number matches: A3447 or A3719 or A3721 or A3720
- Or verify that Model Name is: iPhone Duo
Make sure you select the correct model to avoid installation errors
Apple's firmware list for the iPhone Duo starts with iOS 27.1 (Oct 22, 2026), which is also the newest build published for it so far.
That is 1 release in total, spanning 0 days between the first and the most recent build.
iOS 27.1 is still being signed by Apple, so it can be restored, reinstalled, or updated to with Finder, iTunes, or the Apple Devices app right away.
Every build Apple has published for this device is listed below with its original Apple download link, build ID, release date, and checksums, so an older release can still be verified or archived after Apple stops signing it.
Across that history the device has received 1 major iOS version: iOS 27 (1 release) .