Material: Synthetic leather. Sewing type: Machine-sewn. Chamber: Butyl. Weight: 280 grams. Recommended use: Volleyball. Circumference measurement: 65 centimeters. Competition-grade specifications, precisely tailored to professional needs Professional-grade performance, helping you advance your skills Suitable for multiple scenarios, seamlessly transitioning from the training field to the competition field Professional competition-specific: Certified for use in multiple domestic competitions, suitable for provincial and municipal professional volleyball leagues and various officially certified events, meeting the stringent requirements for equipment in formal competitions, enabling players to perform at their best on the field. School team selection and improvement: Middle school, high school, and university volleyball teams can use this volleyball for standardized training, allowing players to adapt to competition-level ball feel in advance, gain an advantage in selection and inter-school competitions, and cultivate professional athletic habits.