Choose what you want this is only each not pair so if you want might gem i will give you 1 might gem depends on how much u will buy 
Might Gem - Increases the applied Mantra's posture damage by 10%. This effect has no cooldown.

Allows your Mantras to proc the Ascended Outlaw Set Bonus, as well as the individual equipment Talents from the Hat, Robes, and Boots of the aforementioned set.

Wraith Gem - Applies the Wrath status effect on hit, increasing your critical damage

Allows your Mantras to proc the Reinforced War Set Bonus, as well as the individual equipment Talents from the Helmet, Plate, and Boots of the aforementioned set.