Durotan's Battle Harness

Durotan's Battle Harness is a plate chestpiece that was handed down through eleven generations of Frostwolf clan leaders. Crafted of heavy plate mail connected by chains, the harness bears the image of two white wolves facing one another on its front. The harness' last wearer was Durotan, who wore it during the orcs' assault on Telmor. It would have been passed down to Durotan's son and grandson, but at some point it was lost to time. Orgrim Doomhammer believed the harness to have been scavenged or lost to the elements.

Source
Durotan's Battle Harness drops from Captain Skarloc in the Escape from Durnholde Keep instance of Caverns of Time.

Speculation
It's possible that Aedelas Blackmoore took it from Durotan's body when he found Thrall and later gave it to Skarloc.