SKLZ Impact Practice Baseballs are designed with the player in mind. Constructed with proprietary pop-back material similar to the material used to make car bumpers, Impact Baseballs keep their shape and won't crack like standard practice balls even after thousands of swings. A great alternative to whiffle balls, you can feel confident about the durability and performance of Impact Balls. Built to provide instant feedback on contact, they help hitters finetune their swings to find that all-important sweet spot to deliver a better game. The SKLZ?? Impact Ball also features a standard 9" circumference. Heavier than traditional practice balls for more feel, but utilizing a limited flight designed for easy retrieval this ball sets each player up for success. These baseballs hold up against any type of bat and are suitable for any level of player. Give yourself or your players the tools they need before stepping up to the plate, SKLZ Impact Practice Baseballs are the perfect tool for warm ups or practice.