The 10V-Output voltage is implemented through 3 switching steps. By an internal potentiometer the desired tension value can be adapted at stage 1 and 2. Stage 3 gives the maximum output voltage of 10V to the EC fan. The On/Off function is realized via 0-position. The 3-Stage Potentiometer is suitable for the on-wall and in-wall mounting. All necessary components are already included in the scope of delivery.