The Gauntlets of Ultramar are an ancient pair of master-crafted Power Fists, accompanied by a set of ornate shoulder plates (compatible with both Artificer Power Armour and Terminator Armour) and a set of built-in Bolters that are as deadly as a Storm Bolter. The Gauntlets' true origin is unknown; all that is known about these relics is that they were taken back from a fell Champion of Chaos by the Primarch Roboute Guilliman of the Ultramarines after the Gamalia Reclusiam Massacre, who afterwards often used them in combat. No Adeptus Mechanicus Magos has ever succeeded in penetrating their armoured shell to examine the mechanism within.
As weapons used by Roboute Guilliman in life, the Gauntlets are a sacred artefact to the Ultramarines and their Successor Chapters. They are only ever used by the Chapter Master of the Ultramarines, and at all other times they rest within a crystal case in the Fortress of Hera, the Ultramarines' fortress-monastery on Macragge, in the Temple of Corrections' Shrine of the Great Primarch, on display next to where the mortally wounded body of Roboute Guilliman himself was kept in stasis. Such is the reverence of the Ultramarines for their Primarch that only their Chapter Master, currently the Lord Macragge Marneus Calgar, is ever permitted to wear the Gauntlets of Ultramar. Even the Ultramarines' Chapter Master will only don the weapons when he is called to battle in person, honouring his gene-father with his deeds using these relic weapons in the field.
- Codex: Space Marines (5th Edition), pp. 35, 84, 129
- Codex: Space Marines (4th Edition), pg. 52
- Codex: Ultramarines (2nd Edition), pg. 72