Bayliss 2 x XL Autovent Automatic Greenhouse Window Opener

Essential for greenhouse growing, Bayliss autovents automatically open and close hinged vents providing accurate and continuous ventilation around the clock. Using the energy from the sun the Autovents are designed to mechanically open as the temperature increases. Similarly, as the temperature lowers so do the Autovents Automatically opens and closes hinged vents. "clip-on" model lifting a load of up to 5.5kg (12lbs) giving a maximum opening of approx. 12". The unit measures 11" in length and is in a satin anodised finish. Supplied complete with all the fixings and instructions. The strong metal tube contains a mineral wax which expands with heat,this pushes a piston which opens the vent . As the temperature drops, the wax shrinks and a strong stainless steel spring closes the vent and resets the piston. All Bayliss products are guaranteed for two years against faulty manufacture. They are designed and tested to last for many years and are fully serviceable spare Parts are available.