The Slazenger Challenge was made of high quality leather and entirely hand sewn. It was composed of 25 rectangular panels, joined together in a way that was very similar to the 1958 ball and which differed only in the panel which contained the valve. In the Slazenger ball the valve was in the centre of a small panel between two other, even shorter panels. The remaining panels were the same as the 1958 ball and the inflating system was the latest type valve — latex rubber. The ball provided excellent sphericity, and its composition was adopted over the years by other brands. The balls of the 1966 World Cup were provided in three different colours; white, yellow, and orange. Although the most widely used model was the white version, in the memory of football fans the orange ball of the historic final of Wembley remains the strongest.
Contents courtesy of Worldcupballs.info