In Wrath of the Lich King it is item level 245, requires level 80 and is named Nightsong Shoulderpads. In MoP Classic it is item level 232, requires level 80 and sells to vendors for 1c.
Read from the World of Warcraft client build files.
How Conqueror's Nightsong Shoulderpads Compares
Who It Suits
Leather is the armor type Demon Hunter, Druid, Monk and Rogue wear. With Agility or Intellect, Conqueror's Nightsong Shoulderpads suits Assassination, Outlaw and Subtlety Rogue; Brewmaster, Mistweaver and Windwalker Monk; Balance, Feral, Guardian and Restoration Druid; Havoc, Vengeance and Devourer Demon Hunter.
Transmog Sets
Conqueror's Nightsong Shoulderpads is part of the transmog set Conqueror's Nightsong Battlegear (Druid only). The other 16 pieces:
Items Numbered Next to Conqueror's Nightsong Shoulderpads
Blizzard numbers items as they are created, so the named items next to ID 46157 (46152 to 46162) were usually added in the same batch as Conqueror's Nightsong Shoulderpads: the same quest line, zone, vendor or reward set.