Advanced 1-piece Anti-Colic Air Vent helps reduce colic, gas, and spit up. Multiple nipple holes provide a natural feed, just like mom's breast. Features NUKs SafeTemp indicator, which changes color when milk is too hot. Nipple comes with 3, 6, or 9 holes, depending on flow rate. Flexible nipple moves with baby for a continuous latch. Tritan bottle is BPA-free and is easy to use, assemble, and clean. Includes: 4 Bottles. 2 Replacement nipples. 3 Pacifiers.