Aqua Lung Legend LX RegulatorIf you want the same high performance features and ease of breathing as the Legend LUX but without the pink gold finish, you will find it with the Legend LX. Like the Legend LUX, the Legend LX features the Master Breathing System (MBS). Aqua Lung's Master Breathing System (MBS) is a new, simple and effective way to adjust the breathing performance of your Legend LUX. The MBS controls two functions at one time. It controls the direction of air, which