This product was manufactured exclusively for CMS with Crush-Proof "Phthalate Free" non-PVC Plastic material, using a 2-stage blow molding process to ensure consistency of thickness & quality of the balls. These balls met all new toys safety standard. (Phthalate - a chemical additive has been identified to be a health concern in children"s toys.) ***** For the kids with tons of energies and just want to have fun! And, for the parents (or grand-parents) who would not object to chasing after the balls, this one (or 1000) is for you! ;) Guaranteed Crush-Proof or your Money Back. Bulk-packed in a huge box of 500 balls each. ***** Beware of lesser expensive 2.5" balls, you would need almost twice the count of the smaller 2.5" balls in order to fill the same volume as the 3" balls *****