Palram - Canopia Automatic Roof Vent Opener for Prestige, Grand/Hobby Gardener and EcoGrow Greenhouses

The Automatic Vent Opener was designed to automatically control the temperature in all Rion Greenhouses. As the air inside the greenhouse warms, the vent gradually opens to allow the correct amount of air flow into the greenhouse and closes when the optimal temperature is reached. The vent arm was designed with the use of natural wax that expands as the air gets warmer, to push a piston which raises the window, then contracts as it cools, closing with the use of a spring. The Automatic Vent Opener operates without the use of electricity. Features Assembled dimension: 11" W x 2" D x 2" H Automatically control ventilation Protect your plants from heat exposure Provides gradual airflow Easy to install Heat activated, no electricity necessary Specifications Total Product Weight (Lbs): 1.3 Total Box Qty: 1