Babies and busy parents love Mixie? because hunger simply has no patience. This one-of-a-kind, Dad-invented bottle is so expertly designed, it can be filled in advance and mixed at feeding time. The Mixie formula compartment is a patented, airtight design. Simply put formula in the little compartment, water in the bottle, and when baby's ready, push the button to release powder, shake and blend. The formula compartment lid acts as a free-floating agitator, mixing formula powder thoroughly to prevent any clumping. You can have Mixie ready wherever you go, morning, noon, or night. Mixie is available in both 8- and 4-oz. sizes. Mixie 8 oz. holds up to 4 scoops of formula powder and Mixie 4 oz. holds up to 2 scoops of formula powder.