LEGI Automatic opener for front windows and doors

Growing Accessory - versatile, two-branch, for automatic temperature control in the greenhouse, without the need for electricity, the piston contains wax/oil, The opening can be set between 17 and 25 °C, full opening is at 34 °C, total max. Window weight up to 14 kg, compatible with most square and arched polycarbonate garden greenhouses