World Cup Football Ball

The precise shape and construction of footballs is typically specified as part of the rules and regulations..
The oldest football still in existence, which is thought to have been made circa 1540, was discovered in the roof of Stirling Castle, Scotland, in 1981. The ball is made of leather (possibly from a deer) and a pig's bladder. It has a diameter of between 14–16 cm (5.5–6.3 in), weighs 125 g (4.4 oz) and is currently on display at the Smith Art Gallery and Museum in Stirling.