How to check iPhone firmware version / Baseband version
- Press the Settings from your iPhone SpringBoard to launch Settings Menu.
- Press General from Settings Menu
- Now go to About from General Menu
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- Under about screen you can check iPhone firmware version under Version Label
- By further scrolling down you can check iPhone Baseband version under the Modem Firmware Label
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http://www.iphoneheat.com/2009/03/how-to-check-firmware-version-and-baseband-version-of-iphone/