What update in developers preview is this guys?

[anon(5680040)]

What update in developers preview is this guys?
Im running black firmware in greek
I have the 10517

 

[SB5]

That's just the regular GDR3 as I have that version on my HTC 8X

 

[anon(5680040)]

Yesterday I flashed the greek country variant 10517 black firmware with the nokia software updater and when I signed in the developers preview I had to go to the 10521 version...

 

[Devamps]

Microsoft Update 8.0.10521.155 brings improved battery consumption.