The new ball is a product of four years of design and testing, and looks are about the only thing it shares with its older relative. The original model was comprised of 32 individual panels that had to be hand-stitched together. The new one, manufactured in China and Pakistan, has just six panels that are machine-stitched around a newly designed latex bladder, ensuring a more stable performance from ball to ball.
On the other hand, replicas (sometimes called training balls or gliders) are designed to be just like the official match balls but are much cheaper. Their panels are often stitched rather than thermally-bonded and are made of a different material. However, they’re not necessarily less durable than official match balls. So, they’re the recommended option for most players. https://www.youtube.com/watch?v=j2Xn84L3Kcs