Enriched air nitrox, also known as EANx, is a specialized breathing gas used in scuba diving that contains a higher percentage of oxygen than regular air. This increased percentage of oxygen allows divers to stay underwater for longer periods of time by reducing the buildup of nitrogen in their bodies. Divers who use EANx also benefit from a reduced risk of nitrogen narcosis and decompression sickness, which are caused by the accumulation of nitrogen in the body during dives. The specific percentage of oxygen and nitrogen in EANx can vary depending on the desired depth and duration of the dive, and divers must be trained in its use before diving with it.