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 .
Ismartsim have release one Turbo sim .It can unlock 4.1(baseband 02.10.04) and 4.2.1 (baseband 03.10.01), with unlock sim .It frees iPhone to work on different carriers' network of different countries, compatible with 2G GSM2.5G EDGE3G UTMS3.5GHSPA SIM card. No need to rely on bundled operators' network. Once iPhone is unlocked, it is able to access any 2G/2.5G/3G/3.5G network on the planet.
All apple fans who have the Iphone4(2.10.04,03.10.01) can use the unlock sim unlock his phone ,and can use two sim card , this product have Dual sim card Function.
you can use two sim card ,
DUAL sim card function ,please check it
http://www.mydalle.com/dual-sim-card-for-iphone-4_p975.html





How To use it?
Step 1 : First Turn off your iphone 4.
Step 2 : Put the unlock with your mini sim card into the sim solt .then connect with iphone solt on the left.
Step 3 : Turn your iphone 4 back on ,slide to unlock ,and then you will see a SIM Welcome menu, simply select “accept”.
Step 4 : At the beginning you will be able to see a “no service” message on your iPhone. Now you have to wait for some time to see the signal bar.
Step 5: Once the signal bar appears on the top left corner, dial “112″ and hang-up within 2 seconds , no dial.
Step 6 : Turn your Airplane Mode on and then turn off right away. You will now see a “SIM Failure” message on your iPhone and then you will see “No SIM Card Installed”.
Step 7 : Turn your Airplane mode on once again and turn it off right away again until you see the “No SIM Card Installed” message showing up. You will now see a ‘SIM Failure’ message and after few seconds the signal will show up.
Step 8: The process is complete and now you have your iPhone 4 unlocked on baseband 02.10.04, 03.10.01 using i-smartsim unlock SIM.
However, the process is a bit temporary since if no signals appear, you have switch off your iPhone and follow the steps all over again. The process is for the people who are really tired of waiting for software unlock of iPhone 4 and cannot wait any more.
Package include:
1x i-smartsim unlocking sim with sealed packaging.
1xback cover.
Tell us what you think about this item, share your opinion with other people. Please make sure that your review focus on this item. All the reviews are moderated and will be reviewed within two business days. Inappropriate reviews will not be posted.
Have any question or inquire for this item? Please contact Customer Service. (Our customer representative will get back shortly.)