Belt of Dwarvenkind
Wondrous item, rare, requires attunement · 2014 rules, SRD 5.1
+2 Con (max 20); advantage on Charisma (Persuasion) with dwarves; advantage on saves vs poison and resistance to poison damage; darkvision 60 ft; speak Dwarvish.
Also in the 2024 rules (SRD 5.2).