In Wrath of the Lich King it is item level 245, requires level 80 and is named Nightsong Handgrips. 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 (JournalEncounterItem, JournalEncounterCreature, Achievement) and the Blizzard Game Data quest API.
How Conqueror's Nightsong Handgrips Compares
Who It Suits
Leather is the armor type Demon Hunter, Druid, Monk and Rogue wear. With Agility or Intellect, Conqueror's Nightsong Handgrips suits Assassination, Outlaw and Subtlety Rogue; Brewmaster, Mistweaver and Windwalker Monk; Balance, Feral, Guardian and Restoration Druid; Havoc, Vengeance and Devourer Demon Hunter.
Items Numbered Next to Conqueror's Nightsong Handgrips
Blizzard numbers items as they are created, so the named items next to ID 46158 (46153 to 46163) were usually added in the same batch as Conqueror's Nightsong Handgrips: the same quest line, zone, vendor or reward set.