Window opener will not work if these openers are used anywhere exceeding the temperature 50 (122F) Window opener is also suitable for Orbesen, Gardman & B & Q vents Non-electrical use of solar energy, open or close the greenhouse openings as the temperature rises or falls This offer only applies to a spare cylinder for the full set of Auto Vent Openers you can find it in my shop If you find a product that does not shrink, when it is cold or hot, it may be that the product is being used during the high temperature during transport has reached the maximum length. You only have to put the product in the refrigerator and take out after some time. The stainless steel part is pressed to the end and can be used