Series RTL. Thermostatic valves to shut-off the fluid on system terminals and the control of the return temperature in combination with the specific RTL thermostatic head B9U series . Available in straight, double angled versions and kit (return valve, lockshield valve, RTL thermostatic control head). Coupling to the heating body by means of union fitting “Gostop” (with self-threading gasket ready to use). Available with several finish types.