Description: Prevent overheating of the greenhouse. Ideal do windows in the greenhouse - opens and closes the greenhouse window. Since the temperature changes automatically, it maintains the best growth temperature and prevents the greenhouse from overheating. Non-electric, uses solar energy, opens or closes greenhouse vents when temperature rises or falls. It can be fixed or screwed do greenhouse frame. Do not use this opener in places where the temperature exceeds 50 (122F) Make sure the greenhouse window can be opened freely at least 45 cm (18 inches) Do not place excessive strain on by blocking or obscuring the window Don't dismantle the cylinder. Opener CANNOT stop manually Specifications: Maximum window opening: 45 cmli> Maximum opening approximately:30 li> depending on the adjustment and load Maximum opening weight:7kg / 15lbli> Adjustable opening temperature range:15 - 25 / 60 -77Fli> Size:38 x 9,5 x 9,5 cm / 14,96 x 3,74 x 3,74 inches (approx.)li> The package includes: 1 x automatic do window opener The part shown in the instructions is not included. Please take the real part as standard.