As we know . All iPhone iOS versions except iPhone4 4.1(baseband 02.10.04) and iPhone4 4.2.1(baseband 03.10.01) had been unlocked by ULTRASN0W,But 2.10.4 and 3.10.01 can not unlocked by software . Gevey have release one Turbo sim .it can unlock 4.1(baseband 02.10.04) and 4.2.1 (baseband 03.10.01), with Gevey Turbo sim .Your AT&T Locked phone is free to use . Also it can support 3G network . Internet and Mail.
Like Before firmware Gevey .easy Used . No Jailbreak needed! No software unlock! Not breaking your warranty! All apple fans who have the iPhone 4(2.10.04,03.10.01) can use the Gevey sim unlock his Phone