The search term "ireb+40x+41+421+rc3zip+extra+quality" directly points to a specific and popular release of the iREB tool. This version, officially titled , was a widely used build for restoring custom iOS firmwares.

: Refers to iOS firmware versions 4.0.x , 4.1 , and 4.2.1 . These were the peak eras for devices like the iPhone 3G, iPhone 3GS, iPhone 4 (GSM), iPod Touch 2G/3G/4G, and the original iPad.