What does GPP unlock mean?
GPP Sim v5.1 is programmable to unlock all GSM iPhone 4S in the world. It is default to unlock USA AT&T iPhones. For iPhones from other carriers, a special sim card (GPP base sim) is provided to help programming.
What is the difference between an unlock phone and a factory unlock phone?
Difference Between Factory Unlocked Phone and Unlocked Phone.
-A locked phone is tied to one specific carrier and therefore can't be used with other wireless network providers.
-A factory unlocked phone and unlocked phone can both be used with a SIM card on any network.
What is GPP openline
Brand New GPP Sim for iPhone 4S Unlock, works with iOS 6.1.3 , 6.1.2 , 6.1.1 , 6.1 , 6.0.1 , 6.0 & 5.1.1 CDMA and GSM and LATER OS. NO NEED TO JAILBREAK OR DIAL 112. Supports picture mail, text messages and 4G internet. Package includes programing sim used to program your GPP to ANY GSM or CDMA carriers.
GPP Sim v5.1 is programmable to unlock all GSM iPhone 4S in the world. It is default to unlock USA AT&T iPhones. For iPhones from other carriers, a special sim card (GPP base sim) is provided to help programming.

What is the difference between an unlock phone and a factory unlock phone?
Difference Between Factory Unlocked Phone and Unlocked Phone.
-A locked phone is tied to one specific carrier and therefore can't be used with other wireless network providers.
-A factory unlocked phone and unlocked phone can both be used with a SIM card on any network.
What is GPP openline
Brand New GPP Sim for iPhone 4S Unlock, works with iOS 6.1.3 , 6.1.2 , 6.1.1 , 6.1 , 6.0.1 , 6.0 & 5.1.1 CDMA and GSM and LATER OS. NO NEED TO JAILBREAK OR DIAL 112. Supports picture mail, text messages and 4G internet. Package includes programing sim used to program your GPP to ANY GSM or CDMA carriers.