Filled with a mysterious, completely non-toxic, jelly-like compound, it's strong, durable and won't break open; always returns to its original shape. Hypoallergenic and completely safe, it contains no BPA, phthalates or latex; cleans easily with soap and water. Makes a great gift & is perfect for schools, party favors, special needs, the office, stress relief and so much more! A great fidget toy; appropriate for those with ADD, ADHD, OCD, Autism and anxiety; helps promote focus, attention and centering.