restoring iPhone

[Tech198]

When restoring in iTunes, is the .ipsw (image) file is this tired to the serial number of just the specific model of the device being restored onto ?

eg... if u have two iPhone 6's can i use one already downloaded image to restore both of them or would i nee to re-download for each separately ? (basically saving bandwidth)

 

[Newtons Apple]

One backup will do both.

 

[Applejuiced]

If they are both the same iphone model then it will use the same .ipsw to restore and it wont ask you to download it again.
If you have an iphone 5 and an iphone 6S Plus for example itunes will download different firmware files for each device to use in order to restore.