Say 'goodbye' to lumpy protein shakes and 'hello' to smooth, great-tasting drinks. The BlenderBall wire whisk moves freely inside the bottle as you shake, battling even the thickest ingredients with ease. Pro Series features odor-resistant Eastman Tritan, a rounded base, and the all-new SpoutGuard. The patented mixing system uses the BlenderBall wire whisk. This shaker bottle is 100percent leakproof. The adjustable carry loop lets you hold more when your hands are full and provides a convenient place to attach your keys while at the gym. Made from the highest quality materials. This shaker is BPA and Phthalate free. Easy to clean and dishwasher safe. Embossed ounce and milliliter markings helps you keep track of your intake. Get the best-selling shaker bottle on the market. Holds 28 ounces not including the BlenderBall and powders/supplements. Why the Whisk Ball? Unlike stationary mesh grates or other in-lid elements, the BlenderBall whips around inside the bottle as you shake. The BlenderBall is springy and bounces off both the top and the bottom of the bottle, working against the liquids. Made from electropolished, 316 grade stainless steel, the same material used in surgical instruments and implants. Add ingredients like peanut butter, applesauce or yogurt to your protein or meal-replacement shakes for added flavor - the BlenderBall whips them in with ease. The BlenderBall will never rust, chip or peel. Every BlenderBall is manufactured using a unique multistage process designed to ensure safety, quality, and longevity.