Nexus Ring of Dumathoin

Dumathoin is the patron of mountain dwarves,
and the dwarf deity of mining and underground exploration. He is also the protector of the
dwarven dead.
1) Immune to claustrophobia.
2) While underground Darkvision +30 feet.
3) May cast silence once per long rest.
4) If Mountain Dwarf, +1 Con.