This industry leading 28 oz shaker bottle is the best-selling shaker bottle on the market with its iconic design, leak-proof seal, and wire whisk blender ball. The wire ball whips around the inside of the bottle as you shake, delivering industry leading mixing. Add ingredients like peanut butter, applesauce, or yogurt to your protein shake or meal-replacement. These shaker bottles are made from the highest-quality materials, and have always been, BPA- and phthalate-free. With the shaker bottle's classic screw-on lid and secured flip cap, you can be assured of always having a dry gym bag and car seat.