The Baden Lexum 15-0 Leather Game Volleyball has a 2 ply butyl bladder to ensure air retention. This official size and weight leather game volleyball also has a state of the art valve and valve housing that reduces sting, ensures perfect balance and secures air retention. The reinforced poly-cotton liner on this indoor volleyball helps to provide softness during play. This ball is approved by both the USAV & NFHS. When you see the name Lexum on the ball you know that this ball bares the "Mark of the best"