Unlike the standard classic 10mm pistol, Ultimatum possesses a black finish and intricate engravings. On the right side of the gun are engravings of dice, four-leaf clovers, flames, and a Vault Boy face with the following inscription on the barrel:
“A bullet is worth a thousand threats
and I have twelve”
On the left side of the gun are engravings of trees and crows, a bottlecap, and flames with the following inscription on the barrel:
“Be not afraid of any beast, no matter what the size
When danger threatens, wield me, and I shall see to its demise”
On the top of the gun are engravings of the Sole Survivor, a deathclaw arm and multiple Gunners logos. Lastly, on the back of the barrel behind the sights is an engraving of a radiation hazard symbol. Right above the muzzle is an engraving of the words "LOOK HERE."
Due to the unique model used for these engravings, Ultimatum cannot be equipped with barrel modifications. By default, it carries the glow sights, survivor's grip, and muzzle brake modifications. It possesses the "Irradiated" Legendary effect, adding 50 radiation damage to every shot.