OFFICIAL SIZE & WEIGHT : These balls are constructed at official 9.0" size & 4oz weight to give your games a more authentic feel GREAT FOR TEEBALL : These Pro Brite Tee balls are perfect for any young teeball player to practice their catching and throwing skills. SPONGE RUBBER CORE TECHNOLOGY : Our solid sponge rubber core provides the lightest official ball possible, perfect for tee ball practice and training PERFECT FOR PRACTICE : These balls are great for practicing indoors and out. The solid construction ensures that balls will fly straight and true PLAY SAFE : Our solid sponge rubber makes throwing and catching safe for young players