Apple sells two unlocked smartphones: SIM-free iPhone 6 and T-Mobile gadget in its online store in the United States. What is the difference between these two models? Are they similar or identical? Some customers wish to get the answers, so we are here to explain to you what the difference between SIM free and unlocked iPhone 6 / 6 Plus from its T-Mobile version is. This is the only carrier that offered both iPhone 6 Plus and 6 to be used with some mobile companies around the world. Both iPhone 6 SIM-free vs. T Mobile are sold at $649 for the 16GB 6 model and $749 for the same space capacity iPhone 6 Plus. So is there a big deal or not? You might think that SIM free unlocked T-Mobile iPhone 6 Plus / 6 is the same as T-Mobile smartphone, but you are wrong. These two models are different. According to Apple, T-Mobile iPhone 6 Plus is available as model A1522 while the same unlocked iPhone 6 Plus comes as A1524; and T-Mobile iPhone 6 comes as A1549 while unlocked model is named A1586. While both versions support the same frequencies there is a big difference between them. Unlocked and T-Mobile gadgets come with support for different bands: TD-SCDMA and TD-LTE. The SIM-free models support more mobile companies across the world than the T-Mobile iPhone 6 and 6 Plus. For example, Apple unlocked iPhone 6 will work on China Mobile, Unicom and Telecom networks and T-Mobile iPhone 6 won’t support these carriers. The list of supported mobile operators can be found on the Cupertino-based site or at retail stores. If you are planning to travel abroad and wish to connect through local SIMs you better purchase the unlocked smartphone instead of T-Mobile version [even though this cell phone also supports a huge number of both local U.S. carriers, such as AT&T and Verizon, and worldwide networks such a Bell, Rogers, MTS, Telus, Telcel, Movistar and others].