Marlon 6mm Clear Twinwall Polycarbonate Roof Sheet 6000mm x 2100mm x 6mmPlease note 6mm Twinwall does not have a Class 1 fire rating.Properties Excellent protection: against hailstones, vandalism and accidental damage. Fine optical clarity: clear material maximises light getting into the conservatory - light transmission of 82%. Creates: a bright and spacious feeling environment. Maximises: solar gain. Perfect: for sun lovers. Will: require blinds to prevent overheating in the summer months. High strength: weight ratio. Cost effective: as sheet weight is low, support structures can be lighter providing cost effective buildings.Marlon provides high levels of insulation.