16mm Five Wall Polycarbonate Sheets - Available in Clear, Bronze, Opal and Athermic Heatshield colour shades. Ideal applications include Conservatories, Car Ports, Smoking Shelters, Covered Walkways and Garden Extensions. Clear, Bronze & Opal U Value = 2.6W/m2k. Athermic Heatshield U Value = 1.9W/m2k. Class 1 surface spread of flame. 10 year guarantee against discolouration, ageing and resistance to hailstones.