An Automatic Greenhouse Vent Opener is a device designed to automatically open and close greenhouse vents based on the internal temperature. It typically operates without electricity, using a temperature-sensitive cylinder filled with wax or gas that expands and contracts. As the temperature rises, the opener pushes the vent open to release heat and improve airflow. When the temperature cools down, the vent gradually closes. This helps maintain optimal growing conditions and protects plants from overheating, all with minimal manual effort.