I don't believe it's a public promotion, sorry.
Might be something given out to workers of Aeria, or something.
Those items look awesome tho
I find that to maximise your chances of getting a promo, subscribe to Aeria games under your users settings and also keep an eye out for the main MMO sites, thier page on Grand Fantasia/Aeria games in general.
They haven't had a major promo recently but there have been some really awesome ones in the past.