Heavy Duty, Commercial Grade! These balls were designed & manufactured for the more abusive commercial operations in mind. These balls were just as suitable for any home use by kids over 6 years old, because these balls were soft enough, and yet durable and safe enough to meet the lesser demanding home environment. Each balls was tested to withstand over 150 pounds of weight. Manufactured exclusively for CMS using 100% non-PVC Virgin Plastic Material, both Phthalate* & Lead Free. Using a unique 2-stage blow-molding process to ensure consistency of thickness; quality; smooth seam and surface. These balls meet all new toys safety standard. (*Phthalate – a chemical additive used to rubberize PVC Blended Plastic, has been identified to be a health concern to children and adults). 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 500) is for you! 😉 Backed by an Industry's First "150 Days Triple Replacement Warranty", Guarantee against Crush, Crack or Scratch. Guarantee Crush-Proof or your Money Back. ***** Beware of the less expensive 2.5" balls, as you would need twice the count of the smaller 2.5" balls in order to fill the exact same volume filled with 3.1" balls. ***** Other quantity package available on standard grade balls (for home use only), please check Amazon listings: for 150 Balls = ASIN# B002XXC2VM, for 300 Balls = ASIN# B004HCADOK , for 500 Balls = ASIN# B004GLBB0M. Please contact seller for any additional product details.