Icebane Leggings

Icebane Leggings are quest reward plate leggings that give a bonus to strength, stamina and frost resistance.

Source
Icebane Leggings are quest reward from for the quest  if they have completed the quest. Wilhelm will make you this item if you supply him the components.

The components are:
 * 2 Frozen Rune
 * 2 Blue Sapphire
 * 2 Essence of Water