T-Mobile Band 12 4G LTE

[AC Question]

I am looking at buying the Asus Zenfone 3 to use on T-Mobile, but it does not have band 12 support (it does have 2 and 4). Does this mean I will not get any LTE or just not in certain areas? In other words, will LTE work through just 2 and 4, but be limited in some areas with band 12? If this is the case, in band 12 areas, will I get regular 4G?