UNHO Replacement Cylinder Only Auto Vent Automatic Greenhouse Window Opener for Orbesen, Gardman & B&Q vents This listing is a replacement CYLINDER only Replaces worn out Piston Rod from one or more of your Vent Window Openers. Also suitable for Orbesen, Gardman & B&Q vents Non Electric, uses solar energy, open or close the greenhouse vents as temperature rises or drops Important notice:Do not use this opener anywhere the temperature will exceed 50 (122F)