This helmet could previously be won through the "RARE HELMET LOTTERY BOX", which was available post-Parity Patch, untill it was removed in the holiday update on the 18th of december, 2015.
When equipped this helmet increases your Run Speed and HRV Recharge Rate but at the cost of your character's health.
In-game Description Edit
Standard helmet. Streaks of blood adorn this version of the Overmatch Bonebreaker.