For maximum accuracy and performance in your pitching machine, choose the Jugs(R) Sting-Free(TM) Baseballs. The B3000 Sting-Free(TM) Dozen of Baseballs are the same size and weight of real baseballs for more accurate batting practice, and will not damage your aluminum bat when contact is made. Additionally, these Jugs(R) practice balls feel like a real leather ball when hit and offer a waterproof exterior for added durability. FEATURES: Cover : White synthetic waterproof exterior adds durability and feels like a real baseball when hit Core : Same size and weight as a regular baseball, but hurts less when contact is made Stitching : Realistic white seams Additions : Will not dent aluminum bats or sting hitters' hands League/Certification(s) : Practice only; great for both offensive and defensive drills Balls included in purchase : 12 (dozen) Recommended use : Jugs(R) pitching machines; indoors or outdoors Manufacturer's warranty: : 1 year Model : B3000> Jugs For additional information relating to the Manufacturer's Warranty, please contact 1-800-547-6843.