Images:

gw2-siren's-callgw2-siren's-call-2gw2-siren's-call-3

Set:

Slot Item Name Trading Post Preview Code
Warhorn http://db.dulfy.net/item/26854 GW2 TP [&AgHmaAAA]

Where to Obtain:

Random exotic drop from mobs/mystic forge, can be purchased on the TP