Features:_x000D__x000D_Perfect for your greenhouse window--opens and closes your greenhouse window._x000D_As the temperature changes automatically, maintains the best growing temperature and prevents your greenhouse from overheating. _x000D_Non electric, uses solar energy, open or close the greenhouse vents as temperature rises or drops. _x000D_Can be clamped onto or screwed onto your greenhouse frame. _x000D_Please make sure your greenhouse window can be opened freely by at least 45cm (18")._x000D__x000D__x000D_Specifications:_x000D_Greenhouse Window Opener Kit _x000D_Maximum window opening 45cm_x000D_Maximum opening about 30, depending on adjustment and load_x000D_Maximum opening weight 7kg/15lb_x000D_Adjustable open temperature range 15- 25/60-77F_x000D__x000D_Package:_x000D_1# Automatic Window Opener Kit / Replacement Greenhouse Window Opener Cylinder (You can choose what you want)_x000D__x000D_Notes:_x000D__x000D_Do not use this opener anywhere the temperature will exceed 50 (122F) _x000D_Please make sure your greenhouse window can be opened freely by at least 45cm (18") _x000D_Do not apply excessive loads by locking or covering window _x000D_Do not dismantle the cylinder _x000D_The opener CANNOT stop by manual _x000D_Monitors are not calibrated same, item color displayed in photos may be showing slightly different from the real object. Please take the real one as standard. 1Perfect for your greenhouse window??opens and closes your greenhouse window 2As the temperature changes automatically, maintains the best growing temperature and prevents your greenhouse from overheating 3Non electric, uses solar energy, open or close the greenhouse vents as temperature rises or drops 4Can be clamped onto or screwed onto your greenhouse frame 5Please make sure your greenhouse window can be opened freely by at least 45cm (18").