#html-body [data-pb-style=JM2CA5H]{justify-content:flex-start;display:flex;flex-direction:column;background-position:left top;background-size:cover;background-repeat:no-repeat;background-attachment:scroll}#html-body [data-pb-style=HXX2BWT],#html-body [data-pb-style=JM2CA5H]{border-style:none;border-width:1px;border-radius:0;margin:0;padding:0}The Automatic Vent Opener was designed to automatically control the temperature and humidity levels and provide additional ventilation when needed, making gardening easier. As the air inside the greenhouse warms, the vent gradually opens to allow the correct amount of airflow into the greenhouse and closes when the temperature cools. The vent arm was designed with a metal cylinder containing wax which expands when heated to push a piston, which raises the window, as the air gets warmer, then contracts as it cools, closing with the use of a spring and resetting the piston. All you need to do is to install it on your roof vent window and it automati