Made from 100% food grade silicone, BPA free, primary Silicone material, stain odor resistant, environmental durability. Designed ergonomically for all hand sizes. Easy to carry, which can exercise your finger any time and any where. Easy to clean, simply wash. Strengthen your wrists, improve the dexterity of your fingers, reducing fatigue. Great for wrist rehabilitation, rheumatoid arthritis, arthritis, carpal tunnel, tendonitis, tennis elbow.