A "thermostatic" device is designed to regulate temperature automatically. It senses the current temperature and adjusts heating or cooling systems to maintain a desired level. Common examples include thermostats used in homes and thermostatic valves in plumbing systems. These devices help improve energy efficiency and comfort by ensuring that spaces remain at a consistent temperature. When the temperature deviates from the set point, the thermostatic mechanism activates or deactivates the heating or cooling source, providing a stable environment for occupants.