The OnePlus 6T is the first OnePlus device to penetrate the US market through carriers and the T-Mobile is the first one to offer it. But just like every other Android device sold by the US carriers, there are some restrictions that you need to keep in mind. For starters, the carrier will only be offering the OnePlus 6T in Mirror Black variant featuring 8GB of RAM and 128GB of storage for $579 or $24.17 in monthly payments, respectively. If you don't need the extra RAM or the storage falls short, you will have to get it from OnePlus' official web store. But not all is bad as...
Source: https://www.gsmarena.com/tmobile_offers_an_option_to_unlock_the_oneplus_6t_and_the_bloatware_is_limited-news-34051.php