Early Scuba sets have been basically a set of harness straps connected to a cylinder or manifolded team of cylinders, by using a regulator linked to the cylinder valve. The Bonex HP DPV is in about a similar course since the Italian Suex varieties, currently being a compact tow-guiding scooter. https://vuf.minagricultura.gov.co/Lists/Informacin%20Servicios%20Web/DispForm.aspx?ID=11161520