Where did people get Concentration increase Tier2

[zygaming]

I see people are selling them in stacks

So i assume that they have the production skill on it.

So where to get the skills?

[TastyTapioca]

I see people are selling them in stacks

So i assume that they have the production skill on it.

So where to get the skills?


Unfortunately they don't. They're only able to be attained via certain Quests.

[Patchouli]

Lvl 47 repeatable quest gives 2 Concentration Tier2s.