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.
The flight of the ball is accurate to the type of kick that put it into motion because of the 12 panels pieced together flawlessly. The Aerowtrac grooves allow the ball to soar through the air swiftly. The interior bladder is restricted to produce a healthy sphere full of air. The shape is retained even through heavy use and harsh playing conditions.
Besides just its sleek exterior, the Adidas Starlancer is crafted with longevity in mind by the nylon being wound internally and assembled through machine stitching to provide it with an extra level of strength. The exterior is made of TPU material, which is ideal for resisting cuts and scrapes. The bladder which holds the air is Butyl, which works wonders in keeping the shape of the ball perfect at all times.
First of all these balls are good because they are high quality and by having such soccer balls you won’t need to buy new ones so quickly, because these are durable and you will use them longer. They are not just durable, with them you also have better touch with the ball and you can handle easier and better the ball. It is sure easier to train and improve ball control with professional soccer ball.
Today's footballs are more complex than past footballs. Most modern footballs consist of twelve regular pentagonal and twenty regular hexagonal panels positioned in a truncated icosahedron spherical geometry.[4] Some premium-grade 32-panel balls use non-regular polygons to give a closer approximation to sphericality.[12] The inside of the football is made up of a latex bladder which enables the football to be pressurised. The ball's panel pairs are stitched along the edge; this procedure can either be performed manually or with a machine.[5] The size of a football is roughly 22 cm (8.65 inches) in diameter for a regulation size 5 ball. Rules state that a size 5 ball must be 68 to 70 cm in circumference. Averaging that to 69 cm and then dividing by π gives about 22 cm for a diameter.

This can be used as a great option for goalkeeper training as well. Why? Look, you can hardly see the lines on this ball, hence you won’t be able to guess the direction by only seeing the spin of the ball. That means as a goalkeeper you will have to give full concentration to detect the direction of the sliding balls. This is obviously helpful if you are a goalkeeper, and looking for a sliding challenge.
Latex bladders are one of the best materials when it comes to ball construction. However, with latex bladders, air won’t last as long as butyl bladders and will need more attention for proper inflation. Butyl-blend bladders hold in the air much better, but they are harder and less receptive in play. Mid-priced balls will usually have a mix of butyl and rubber.