Fort 2 Automatic Spring Greenhouse Window Roof Wind Lift Heat Kit Automatic Ventilation System for Greenhouse

Two springs, not one, can support a massive 15 kg load Specifications * Adjustable open temperature: 15°C to 23°C (59 to 73°F) * Fully open temperature: 35°C (19°F) or higher * Fully open distance: 45 cm * Maximum opening weight: 15 kg (30 lb) * Temperature changes in your greenhouse will trigger the opening mechanism