The Shake It Large Capacity 28 Oz. Shaker Cup Uses A Ball That Helps Combine Protein Or Other Drink Powder With Liquid And Break Up Lumps To Give You A Smooth Drink. Be Sure To Add The Liquid Before You Add The Powder To Prevent It From Clumping On The Sides Or Bottom. Features Include Ounce And Ml Measurements, A Wide-Mouth Opening For Easy Cleaning, Integrated Carry Handle And A Flip Cap That Stays Out Of The Way When You Are Drinking. BPA-Free And Fits Most Car Drink Holders.