Ring of Hold Breathing (3.5e Equipment)
From D&D Wiki
Ring of Hold Breathing: An ornate ring of silver, its wearer needs not breathe for up to one hour per day, the time divided how he wishes. It can prevent the effects of suffocation and drowning. The wearer must hold his breath to gain it’s benefit.
Moderate transmutation;CL 7; Forge Ring, gust of wind; Market Price: 6,500gp