Similac SimplySmart, designed by experts in infant nutrition. Similac partnered with moms to design one bottle that has it all. This unit includes 2 level 3 fast flow nipples which are recommended for older babies (6 months old). This naturally shaped nipple is designed for feeding between breast and bottle and includes features like the Intellivent, a venting system designed to reduce baby"s excess air intake for less fussiness and gas.