Place between your new SIM card and the iPhone’s SIM tray, wait 30 seconds and your iPhone will show signal and allow you to use mobile data including 4G!
iPhone Unlocking Sims. It only requires you to add a small piece of plastic (a sim imposter). And if like magic your handset will work with any network provider. This is good if your full permanent unlock isn’t being accepted for some unknown reason or your handset is locked to a foreign network were factory unlock is not available. This is considered a temporary solution, but for lower IOS devices iPhone 4, 4S which will not update its IOS anymore so the unlock can be considered permanent.