Dr. Brown's wide bottle with nipple and spout, 270 ml, in rainbow colors, suitable from 6 months. The "Bottle to Cup" set makes the transition from nipple to bottle and to the cup spout easier. The bottle features a level 3 spout and a leak-proof silicone spout. Please remove the internal bottle vent before using the spout in the bottle. The leak-proof silicone spout prepares your baby to drink from a cup. It is best to use Dr. Brown's venting system during feeding so your baby can enjoy all the health benefits: it has been shown to reduce colic in children. The venting system prevents the formation of air bubbles in the milk, which helps to avoid colic, spitting up, and gas. The patented venting system effectively reduces the oxidation of breast milk and formula, promoting the stability of essential nutrients such as vitamins C, A, and E, as well as lipids. (Based on university research) The complete bottle venting system allows for vacuum-free feeding, similar to breastfeeding.