Apple is shipping four different models of iPhone for its yearly refresh. The iPhone 6s sports two models—A1633 and A1688, while the iPhone 6s Plus feature models A1634 and A1687.
Although both iPhones in the 6s and 6s Plus lines are virtually the same, the model numbers differentiate the cellular LTE band capabilities of each phone. Thus, by familiarizing yourself with each model number, you can learn what networks each phone will support.
Why is this important? Say you wanted to order a new iPhone 6s in rose gold. As you might have heard, rose gold is proving to be very popular, and is selling out quicker than some of the other iPhone color options. Rose gold 64GB iPhones designated for T-Mobile and Verizon are now on backorder for 2-3 weeks.
But some rose gold models remain available—for example, some Sprint-designated rose gold models are still shipping on 9/25. By using our knowledge of iPhone model numbers, we might still be able to obtain a rose gold iPhone 6s to use with a provider like T-Mobile or Verizon by purchasing the Sprint model...