Features:The small exercise ball for between knees is the ideal tool to improve body rotation efficiency and swing speed while also helping to adjust your posture and solve forearm bounce issues.The 9 inch pilates ball is built to assist in boosting body rotation and ball hitting speed giving you a fitness ball that helps you build and maintain contact during throws and catches thereby exercising your arms core strength.Specifications:Material: PVCColor: blueSize: approx. 9 inches in diameterPackage includes:2 x Pilates balls1 x InflatorNotes:Manual measurement please allow slight errors on size.The color may exist a slight difference due to different screen displays.