Chef Buddy (80-01215A Double Layer Auto Mixing Travel Mug with Tornado Action TORNADO ACTION-To use, add protein powder or other ingredients before liquids. Then hold down the on/off switch, located conveniently on the base of the cup, and the powerful mixing blades in this tumbler quickly blends your drink in a circular motion! EASY TO READ MEASUREMENTS-Both milliliters and ounces are clearly marked on the travel mug to help track your liquid intake. The dual layer design also provides insulation, making this bottle an excellent tool for weight loss and health or fitness! GREAT FOR TRAVEL-This lightweight battery-operated mixer is equipped with a spill-proof lid- perfect at home, the office, or in the classroom. The portability makes it a perfect gift for busy moms and dads, college students, or friends and family! HOT AND COLD DRINKS-The self-stirring mixer is durably made for deliciously crafted beverages time and time again. The clear acrylic tumbler is safe for a variety of drinks, including coffee, hot cocoa, iced tea, baby formula, protein shakes, and more! PRODUCT DETAILS-Holds up to 16 oz of liquid. Dimensions: 3 x 2.5 x 8.75. Requires 2 AAA batteries (not included). Battery compartment is water proof. To wash: add warm soapy water inside, spin, and wipe clean. Materials: BPA free plastic.