Very nice plant, Yves! All the yellow at the base of the segments is great, other individuals I've seen are less colorful. Is it a seedling?
The lip of this species is really cool; it's fuzzy, very dark red/black, and mobile, sort of like a Bulbophyllum. I'd love to know what kind of pollinator it has in the wild.
Joann, Andy's and Carolina carry this one, though both call it by the synonym tuananhii (trantuanii was published earlier and is accepted by Kew). If you buy from Carolina get one in bloom if it's available...
--Nat