The TWA is a small actuator for electrical on/off - controls to activate several types of valves and floor heating manifolds. The actuator is equipped with a visual position indicator to show the open or closed position of the valve. The TWA range covers actuators for 24 V (SELV) or 230 V supply in both normally closed (NC) or normally open (NO) versions (valve positions with no supply voltage to the actuator), and the 24 V TWA for RA valves also comes in a NC/S-version with an end-switch.