The timber is Pressure Treated to give a 15 year Anti-Rot guarantee and the panel can also be used without gravel boards. The panel is Manufactured from FSC certified timber. Available in 4 heights - 6ft (1.80m), 5ft (1.50m), 4ft (1.20m) and 3ft (0.9m) This product is FSC certified (FSC-C00427). Please visit the link below for more