Official NFHS and USA Volleyball Approved Volleyball with Wilson's I-CORE Technology. This Indoor Volleyball Is the Official Size and Weight for Competition and Has a Composite Leather Cover with a Latex Power Lining Along with V-tec Seams. Official Size and Weight for Competition - Circumference: 25.5" - 26.4"; Weight: 9 to 10 ounces USA Volleyball and NFHS approved i-COR Technology for superior power and control Microfiber Composite Leather with V-Tec Seams and Latex Power Lining All balls are cured in a spherical mold to ensure the ball is perfectly round and extremely durable