The Vitavia Automatic Louvre Opener will open and close your louvre window with precision, therefore ensuring your greenhouse has automated aeration without the need of electricity. As the temperature inside the greenhouse increases the automatic opener will push open the louvre window and will retract as the temperature decreases. An automatic opener is ideal for when you are away from home as windows can not be opened manually which is necessary in maintaining the best heat and humidity levels for plants in a greenhouse. Plant oil inside the piston expands and retracts with temperature fluctuations to either push or pull the window open or closed. This product is only compatible with Vitavia greenhouses.