The description might be sufficient, but it's inaccurate. You can't say AT&T 850/1900 and T-Mo 1700/2100 in one sentence. It's not the same context. You can s

The description might be sufficient, but it's inaccurate. You can't say AT&T 850/1900 and T-Mo 1700/2100 in one sentence. It's not the same context. You can say AT&T 850/1900 and T-Mo 1700. The point is it's more difficult for phone manufacturers to make world phones for AT&T because they have to use up two bands just for AT&T, and those two bands are not commonly used in Europe or Asia.