Iron gauntlets that Thor must wear to wield Mjölnir.

Járngreipr, the iron hands or gauntlets mentioned in the Eddas, are one of Thor's three principal attributes alongside Mjölnir and the strength belt Megingjörð. Without them he cannot lift the hammer.

The gauntlets are listed in Gylfaginning among the things whose price cannot be matched. They underline Thor's character as a god whose power depends on the right tools, not divine nature alone.

Attestations

Snorri Sturluson, Gylfaginning kap. 21 (ca. 1220)
Snorri's summary of Thor's three most important possessions.