Editing Scuba set (section)

===Hose swivels===
Swivel fittings between the low pressure hose and the second stage inlet connection are available which allow either a fixed angle or a variable angle between hose and demand valve housing. These allow a wider range of comfortable hose routings, particularly useful for stage and side-mount cylinders, but add another potential point of failure at the swivel joint. Swivels are also occasionally used between first stage and hose to provide better hose routing, but these usually have a fixed angle. The two types are not interchangeable, and can be recognised by the thread and O-ring arrangement.<ref name="Mark" />