Planning to snag that maxed out HTC One in the US? AT&T is where you'll have to go, then. The 64GB variant of the device is an AT&T exclusive, as revealed by a recently uploaded video to the service provider's YouTube channel. The 32GB One will also be on offer, though there's no word on exactly how much either will be priced at or an exact arrival date -- April is the most specific we've heard from HTC. Verizon is also expected to carry the device, of course, but AT&T will certainly be "the one" for folks needing that doubled storage space on a two-year agreement. Check out the video for yourself after the break.