rubber basketball: rubber cover, polyester winding, rubber bladder, official size and weight (1) Material: rubber of good quality.(2) Official Size & Weight: 7#, ... 6#, 5#, 3#, 2#, 1#.(3) Bladder: made of good quality rubber/butyl, and ... export, so it's of strict quality control .(7) Bounce well, strong elasticity. So please hold, ... because we are professional factory. Rubber Basketball