Soccer ball covers are meant to protect the construction of a ball, and make it more durable and long lasting. Manufacturers use two types of materials, mainly polyurethane (PU) or polyvinyl carbonate (PVC). PVC is the cheaper and much affordable variant, but it is more durable than PU. It has scuff-resistance, which makes it perfect for training soccer balls. PU is used for match balls, since it is softer than a PVC soccer ball and tends to respond better to contact.
Why do some soccer balls get bigger over time? Many soccer balls do tend to get larger over time. Especially lower quality balls! This is due to the pressure of the bladder against the linings and cover. Over time the material and stitching may stretch out causing the ball to become larger. Also, soccer ball abuse may cause the stitching to loosen and the ball to expand.
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