I've been having a tough time trying to figure out Apple's model numbers for their iPhones and what will and won't work on other carriers. I have the 6s that's sold by T-mobile (Model MKR62LL/A) which i think is technically model A1688, but I don't know for sure if this will work on Verizon where I plan to switch to when I pay this off. Can anyone help me in figuring this out?