The QO line are push-in fittings designed and tested to guarantee a working pressure of 350 bar. The compact, innovative design allows for safe, quick and easy assemblies with no need for assembly tools on reduced manifold spaces as well as during difficult assembly operations. The hydraulic tightness between the fitting and the plug is guaranteed by an oring outside of the fitting itself. This feature enables the fitting serviceability in case of oring damage or wear out.