An apparatus for delivering humidified gases has a connection manifold ( 8 ) adapted to connect with inlet ( 5 ) and outlet ( 6 ) ports of a slide-on water chamber ( 2 ) in a single slide on motion. Connection of the gases inlet ( 5 ) and gases outlet ( 6 ) ports as well as any additional electrical and/or pneumatic connections are all made in the same slide on motion. The water chamber ( 2 ) may include inwardly extending elongate extension tubes ( 30,31 ) and at least one of the extension tubes may also have an air bleed aperture ( 33 ) to aid filling of the chamber ( 2 ).
