Precision machined connector parts that link systems, compatible with small, medium and manifold assemblies. Shapes include square-flange connector bodies with corner mounting holes and an externally threaded barrel ending in a serrated crown; brass-coloured parts with hex bodies, threads and slotted pin ends; silver turned sleeves with toothed inner rings and grooved outer walls; and silver rings with internal threads, knurled outer bands and small radial holes. Each part is made to exact tolerances and material specifications for reliable performance.