Second Wind 2014
Ring, common
This plain, copper band holds a clear, spherical crystal. When you run out of breath or are choking, you can use a reaction to activate the ring. The crystal shatters and air fills your lungs, allowing you to continue to hold your breath for a number of minutes equal to 1 + your Constitution modifier (minimum 30 seconds). A shattered crystal magically reforms at the next dawn.
Source: Vault of Magic (Kobold Press) · License: OPEN GAME LICENSE Version 1.0a details