Flush-mounted thermostat suitable for all standard switch ranges. Polar white glossy, 55x55 cover without frame. Suitable for controlling central heating, hot water underfloor heating, warm air heating, etc. Very large display with white backlighting that is off and briefly on after pressing a button. Single-line text display for self-explanatory operation. Simple switching between two temperatures (e.g., comfort and setback temperature). ECO input for activating a freely adjustable temperature, e.g., for night setback. Short-term timer (party) for changing the temperature by the hour. Energy consumption display (switch-on time multiplied by costs). Frost protection. Unauthorized access protection. PWM or two-point control method. Adaptation to de-energized open valves. Heating or cooling adjustable. Valve protection. Installation in a 55 mm flush-mounted box.