I found this cloak upstairs in Durgan's Battery
It gives +5 DR for Shock and Burn
When equipping it on Durance, it also seems to lower the Burn DR of Durance's robes, resulting in an overall penalty to Burn DR
Save: http://www.dropbox.com/s/k7jrrzyk4um6z6f/846b78ab096e48aba76bd8104acdab87%2013724566%20DurgansBattery.savegame