Inter control smarty plus thermostats 16a 230v inter control 161471006d10 this smarty plus thermostat uses a vaulted bimetallic disc that is in direct contact with the mounting plate so the sensor reacts quickly to changes in temperature when the set temperature is reached the bimetallic discs operates and opens the electrical contacts upon cooling the disc snaps back into position closing the circuit inter control 161471006d10 open 80c smarty plus thermostat