Made from only the highest-quality materials, BlenderBottle® brand shaker cups are—and always have been—BPA and Phthalate free. The ProStak’s unique interlocking jars have individual lids, making it possible to carry supplements, snacks, and more—with or without the bottle. With a quarter turn, the Twist n’ Lock™ jars can be quickly attached or detached from the bottle. The covert pill tray locks into any jar lid, allowing you to carry pills and powders in the same jar.