3 Protocol; 4 See Also; 5 External Links . iPhone OS 1.x and 2.x do not use SHSH signatures, and can therefore be downgraded to at any time, even on . Blobs must be stitched into a custom firmware, and restored to in Pwned Download iOS Firmware 5.1.1 (9B206) for iPhone 4S. File Name iPhone4,1_5. 1.1_9B206_Restore.ipsw; File Size 802.77 MB; Device iPhone 4S; Downloaded.