Premium Materials: The stress relief balls uses high quality TPR, the ball skin is thicker, can be stretched, squeezed, not easy to break and easy to clean, the internal filling is PVA material and water, the slow rebound effect is better, if the appearance is stained with dust, you can clean with water, gently rub a few times, and you have a clean stress ball. Valuable Package: You will get 24pcs stress cubes, 8 colors, red, green, purple, dark blue, light blue, yellow, orange, rose pink, three for each color, enough quantity can let you share with family and friends, enjoy the joy of stress balls together. Suitable Size: The squishy balls size is 3.5cm/1.38IN, the size of the stress ball is more consistent with the palm, very suitable for one handed play, better experience, not as small as the mini pressure ball is inconvenient to play, can exercise finger flexibility.Very suitable for children over 6 years old to play.