Phone LTE channels

I'm living in europe and ilooked at HTC one site, i understand that the developer/unlocked devices have the same bands as AT&T.
in the HTC site specs the bands are:
4G - LTE:
AT&T: 700/850/AWS/1800/1900/2600 MHz

So AT&t/dev/unlocked have 700/850/AWS/1800/1900/2600
But in this site:
it says that the bands are 17/4/2/5 which are 1700, 1900, 850 and 700.
What are the right specs?