Material: The stress balls fidget toys are made of non-toxic food-grade silicone material, and size is 2.75inch/7cm, so it is safe for kids to play freely and safely, also no need to worry they will eating inside by mistake. Unique Design:This 3D stress relief ball combines the design of the latest fashionable push pop fidget toy. There are bubbles on the surface of the ball and when you pop the bubbles they will make good popping sound. Hand Training toy: The stress balls for kids is a Good hand training toy. It can help children to improve fine motor skills, concentration. Parents can have fun playing with your kids. Enjoy at Any Time: the diameter of this squeeze ball is about 2.75 inches, very portable, you can hold a ball with one hand and pop, suitable for offices, homes, libraries, stations, physiotherapy rooms and travel, etc to enjoy the fun of stress relief anytime, anywhere.