It grants a +5 bonus to Melee Weapons and a +1 bonus to Perception. Visually, it differs from the average Fiend battle helmet by the bighorner horns, it's missing the feathers on the horns, there is a key hanging from each horn and the symbol on the skull is different.
Alternatively, it is given by Motor-Runner if one decides to tell Hsu that Motor-Runner is "dead."
It can be pickpocketed. First, reverse pickpocket a headgear with 3 or higher DT, and go to another zone and wait for three days. Then return to pickpocket it. Hsu will accept it as if one has an arrangement with Motor-Runner. It can be utilized when one can't speak with him and want to keep him alive and still complete the quest.
One must give it to Colonel Hsu to end the associated quest, earning NCR fame and caps but lose the helmet unless it bugs. Freeing Ranger Bryce Anders and speaking to Hsu is enough to go from "liked" status with the NCR to "idolized" (regardless of dialogue choice), so turning over the helmet is entirely optional due to numerous other ways to raise reputation.
Due to its quest item status, it can't be tossed even when broken. Without the aid of console commands, this item can remain indefinitely in the Courier's inventory.
As it is a quest item, it will not be removed from the Courier's inventory when entering the Sierra Madre.
Sometimes the helmet will give a +2 Perception and a +10 Melee weapons bonus. [verified]
Motor-Runner's Helmet will sometimes remain in the Courier's inventory even after the associated quest is completed. It is a quest item: it cannot be dropped, placed into a container, or given to a companion. Simple console commands can remove this item from the Courier's inventory. [verified]
Killing Motor-Runner without having been assigned to do so will cause you to fail a quest. HOWEVER, you can still give the helmet to Hsu for the quest XP (the helmet won't be removed from your inventory though the option appears to exist to drop it. Clicking the "Drop" button will not drop the helmet, and you will simply get the Quest Item error message). [verified]
Sometimes, in the add-on Dead Money, when this helmet is in your inventory, the game will crash when you find the 'source' of the signal, and the 'trap' is sprung. [verified]