Using solar energy to open and close all of our vent openers are ideal in aiding to help regulate greenhouse temperatures. The Optivent is constructed of aluminum and stainless steel and is fitted with two pull back springs which enable the greenhouse vent to close quickly when the temperature drops. It is also ideal for light windows and in areas of moderate winds. Temperature range 16-25 Celsius.
SORRY, OUT OF STOCK FOR 2014. WILL BE BACK IN STOCK EARLY 2015.