Automatic Greenhouse Window Opener, Vent Opener 7kg, Accessories Solar powered, opens from 15C, fully open by 38C, 45 cm lift, double spring, replaceable wax cylinder, Designed in the UK

Opens and Closes Itself, No Power Needed: An automatic greenhouse vent opener with a sealed wax cylinder that expands as the air warms and contracts as it cools, lifting the vent on hot mornings and closing it at night, no electricity, no batteries. Opens From 15C, Fully Open by 38C: The greenhouse vent starts to lift from around 15 degrees, reaches its full 45 cm opening by 38 and closes again 5 to 10 degrees lower, so the greenhouse holds a steady temperature instead of flapping all day. Double Spring Build, Lifts Up to 7 kg: Two return springs share the load, so this greenhouse automatic window opener suits standard aluminium roof vents and side hung windows on glass, polycarbonate, galvanised steel and timber frames. Self Regulating, Not All or Nothing: As the greenhouse cools a little the vent eases partly shut rather than slamming closed, so this automatic window opener holds the temperature steady through a changeable British afternoon. Replaceable Cylinder, Not a Replaceable Opener: The sealed wax cylinder is rated for 10,000 cycles and swaps out on its own if it ever tires, so a worn part costs a spare rather than a whole new unit, with a stainless steel rod protecting the seal. Off in Seconds Before a Storm: The cylinder removes by hand, so you can take it off before high winds or over winter and refit it in spring without tools or unbolting the frame, the safe answer to the gales that wreck fixed openers. Designed in the UK, Fitted in Minutes: Sized for British greenhouses and weather, working down to around minus 5 degrees, with the factory's own fitting tip, chill the cylinder in the fridge so it fully retracts, then fit it with the vent closed.