Designed for summer collegiate leagues and collegiate practice. The KJ10 ball features a cushioned cork center, dual rubber layers, 50% wool windings, flat seam and Grade A pro level geniune leather cover. This design ensures a well-balanced weight, responsiveness, durability and playability. Compression test results: 266. The higher the compression, the harder the ball. Average college baseball compression = 230 - 280. Coefficient of Restitution (COR) test results: .552 The higher the COR, the more liveliness the baseball. Average college baseball COR = 525 - 560.