You can download the iPhone Firmware Flash Tool from the following links:
Free, Ad-supported (Banner ads), Windows Only. Official Link: www.3u.com iphone firmware flash tool link
Before using the iPhone Firmware Flash Tool, make sure to: Informative Report: iPhone Firmware Flash Tool Link You
The iPhone Firmware Flash Tool is a free software application developed by Apple Inc. that allows users to restore their iPhone, iPad, or iPod touch to its factory settings or update to the latest firmware version. The tool uses a USB connection to communicate with the device and flashes the firmware image to the device. Ad-supported (Banner ads)