The 20mm thick cushion on the seat allows for a comfortable playing environment, while the pockets on both sides can hold a cajon brush, music or hand shaker. Universal seat size fits most cajons. Velcro band for one-touch installation. Pad part: Width 10.6 inches (270 mm) x Height 9.8 inches (250 mm) x Thickness 0.8 inches (20 mm)