In 1838, Charles Goodyear introduced vulcanized rubber, which dramatically improved the football. Vulcanisation is the treatment of rubber to give it certain qualities such as strength, elasticity, and resistance to solvents. Vulcanisation of rubber also helps the football resist moderate heat and cold. Vulcanisation helped create inflatable bladders that pressurize the outer panel arrangement of the football. Charles Goodyear's innovation increased the bounce ability of the ball and made it easier to kick. Most balls of this time had tanned leather with eighteen sections stitched together. These were arranged in six panels of three strips each.
Changes in temperature will also affect the inflation level of the soccer ball. Extreme heat or extreme cold will alter the shape of the bladder and this will affect the integrity of the soccer ball. Although it doesn’t seem like you could reach an extreme temperature that could do this to a soccer ball, just leaving a ball in your trunk or the back of a van on a hot Summer’s day will do it.
Only size 5, and size 4 are available for this. Although this should not be a major problem as this is for recreational play and practicing purpose, so kids are ok to play with this as well. In fact, the ball that will be given away to the developing countries will be used by the kids mostly. If you are buying this for an adult go for size 5, and if you are buying for kids or youth players then better go for size 4.
Size 5 is the official size for professional matches. Therefore, this ball is only available in this size. Do not use this soccer ball on concreted areas. Its unique rubber uses Puma Airlock Valve Technology (PAL) in order to facilitate proper airlock technology. This ball features Perimeter Balance Technology (PBT) which enables it to maintain impressive flight characteristics. https://www.youtube.com/watch?v=j2Xn84L3Kcs