Create free fresh air with Skyaxis wind driven turbine roof ventilators. Removes heat and condensation, smells, fumes, smoke and stale air highly effective venting efficiency for residential commercial and industrial buildings. Roof ventilators create a convection current drawing fresh air back into the building. 15 year manufacturers warranty, easy installation, no wiring, no maintenance, corrosion resistant, 100% waterproof. Made from aluminium alloy with flurocarbon polyester coating allowing for it's light weight and durability which maximises spin sensitivity with revolving beginning at low wind speeds. Three sizes available, 300mm, 500mm and 600mm. Please see our website for more information.