[Nitrox](Nitrox.md) is the most mainstream gas mixture. Even if Nitrox is used by confirmed divers, it has still a great popularity because of the easiness of use and because it can be used for recreational dive. Let's talk now about the mixing gas used for technical diving. The Trimix, as its name suggest, is a mix of three different gas : oxygen, nitrogen and helium. It is use for technical, commercial and advanced recreational diving. This force the diver to follow a specific training and be equipped with specific diving computers. Like the Nitrox, the concentration of each gas depend on of the type of dive you'll achieve. We can class Trimix in multiple categories, mostly based on their oxygen concentration. **Links :** * [Trimix - Wikipedia](https://en.wikipedia.org/wiki/Trimix_%28breathing_gas_%28) * [Trimix - Wikipedia FR](https://fr.wikipedia.org/wiki/Trimix) * [Why do technical divers use helium?](https://www.youtube.com/watch?v=uCpUcyJ8E84)