Steam Armor, Variant (5e Equipment)
From D&D Wiki
Armor (Samurai Armor), Very Rare (requires attunement)
Created by shinobi capable of producing steam from their body,
Steam Storage. While wearing this armor, the cost of casting and maintaining Vapor Style: Unrivaled Strength is reduced by 2. Additionally, your jumping distances are doubled, and your swimming speed is increased by 15 feet.