Spalding Never Flat Soccer Ball, White/Navy - Size 4 Stay on the pitch longer with the NeverFlat line of soccer balls. This ball has an exclusive membrane technology that tightens the natural pores in the bladder to improve pressure retention along with a valve cap that eliminates leaks and keeps dirt out. Additionally, they use a proprietary technology called NitroFlate molecules which are injected into the ball, forming a protective barrier against air seepage. This means the ball stays inflated 10x longer than traditional balls. Features:Machine stitched PU composite coverReady for competitive play100% Butyl Bladder and 100% Nylon WindingsSize 4 soccer ball