The set requires a character level of 70. The set can be crafted by the Blacksmith with the Guardian's Jeopardy plan. Prior to Patch 2.0.6., each piece also required one Symbol of the Guardian Brotherhood.
The level 55 equivalent of this set is Guardian's Contingency.
The set consists of just three pieces, all three of which are required to complete the set.
The movement speed bonus doesn't add over the 25% cap.