In Fallout 3, it can be repaired with other Regulator dusters and provides a Damage Resistance of 10 as well as a bonus of 1 to Charisma and a bonus of 5 to Small Guns.
In Fallout: New Vegas, it is a unique piece of clothing providing a bonus of +1 Charisma and +5 Guns, but lacks any Damage Threshold.
The duster outfit seems to consist of a black undershirt and a pair of gray canvas pants underneath a long, brown leather overcoat with the sleeves rolled up above the elbow, a pair of leather gloves on the character's hands, and a pair of motorcycle boots for footwear.
If one has negative Karma, Regulators will occasionally show up to kill the Wanderer for a bounty, at which point a regulator duster can be obtained by killing them and looting their corpses.
If one has the Lawbringer perk and reverse-pickpockets the un-named Regulators inside the Regulator HQ, they will have a new duster in 72 hours.
If the player character takes the Lawbringer perk, there will be a Regulator on a stairway as soon as one enters Arlington Cemetery, as well as a note for Junders Plunkett, who is in the area.