Correct bearings for 12mm rear specialized hub

[Baker]

My sealed bearings have gone on my rear stout 29er wheel after only three months. Any clues as to what size I need as there seems to be lots of choices. I generally buy from wiggle.
Thanks.

 

[outerlimits]

My 2018 base model Roval 27.5 wheels have 6903 LBLU in the rear. And the fronts are 6902 2RS
My hubs are made by Formula and rebaged as Specialized. Higher end Roval wheels hubs are made by DT Swiss and rebaged as Specialized.
Best to pull off the freehub and check tho.

 

[Baker]

Yep 6903 LU so must be a formula hub. Was just going for a ride so wanted to avoid taking the wheel apart but done now.?

 

[outerlimits]

Yep 6903 LU so must be a formula hub. Was just going for a ride so wanted to avoid taking the wheel apart but done now.?

My originals lasted 1800km, the new ones have done 4700km and still going strong.