uPVC 410mm Replacement Fascia Board (18mm Double Square Edge) 5m - Anthracite Dimensions Length: 2.5m. Width: 410mm. Thickness: 18mm. Leg: 35mm overall. Material: uPVC. Guarantee: 10 years. Description The magnum square leg fascia system is a clean, modern style which includes the 18mm thick fascia board and a full range of accessories to ensure a neat and professional installation. The magnum square leg fascia system comes in a wide range of solid colours, woodgrain finishes and fascia widths.