Features:
• The Sponge Rugby Ball weight:30lb.
• The exercise balls are made of high-quality thermoplastic rubber (TPR) and food-grade silicone, which keep it’s original shape after repeated squeeze and stretch
• They can be washed with soap and water, so you can use them for a long time.
• These exercisers can be used to relieve stress, increase the strength of hands, fingers and forearms, and reduce muscle tension. Keep fingers, hands and forearms strong to prevent pain.
• These hand training product are for office trainings,bodybuilding,golf,tennis,squash,racquetball,piano,guitar and other musical instruments