2-Pack Mixie Formula Mixing 4 and 8 oz. Baby Bottles. Mixie Formula-Mixing Baby Bottles are portable, easy, and mess free / Latex free, BPA-free. Formula goes in the little compartment, water goes in the bottle / Colic reducing, silicone wide-neck nipple. At the first cry, simply push the button, shake, and blend / Perfect for travel / Patented air tight design. Set of 2 includes: One 4 oz. bottle / One 8 oz. bottle. Dishwasher and microwave safe / Made in USA.