2 Quad distributing adapters, M16x1, with barbed fittings for tubing 8 mm or 12 mm or 1/2“ ID. Set of two circular quad manifolds with internal baffles for constant water pressure and temperature to all outlets. M16x1 screw thread fittings (which can be fitted with shut off valves), comes complete with all barbed fittings for both 8mm and 12mm/1/2’’ ID tubing.