A harness 10 comprises a back plate 12, a sliding plate 16, a pair of shoulder straps 20, 22 and a belt 18. The sliding plate 16 is slidably attached to the back plate 12 in such a way that it can move longitudinally with respect to the back plate between the extended position and the un-extended position. The shoulder straps 20, 22 are fixed to an upper portion of the sliding plate and the belt 18 is fixed to a lower portion of the back plate. The sliding plate 16 can be fixed at various positions between the fully extended position and the un-extended position. This allows it to be comfortably worn by users of different heights. A valve 28 is provided at the bottom of the back plate 12. In use a cylinder of breathable gas is connected to the valve and it is retained by the back plate 12 and a retaining strap 13. Two air supply hoses, or conduits, 24, 26 are connected to the valve for supplying breathable gas, one to the breathing apparatus of the harness wearer and one to a pressure gauge. The hoses 24, 26 extend substantially longitudinally from the valve 28 and pass through an opening 14 in the back plate 12 to the inside of the back plate. In addition, or instead, one or more of the conduits may be an electrical cable.
The hoses 24, 26 are attached to the sliding plate 16, one being attached to each side. The hoses cross over in the region of the opening 14 and as such the side of the sliding plate 16 to which they are attached is different to the side of the valve 28 from which they leave. There is a longitudinally extending guide channel 34 for retaining the hoses on either side of the sliding plate 16. The guide channels 34 are shaped with projections within and along their length so as to retain the hoses 24, 26 within them. The hoses 24, 26 extend along substantially the full length of the sliding plate 16 and leave the sliding plate in the region of the shoulder straps 20, 22.