Designed exclusively for breastmilk feeding, the Calma bottle from Medela makes switching a baby from bottle to breast a whole lot easier. Its flow control valve feature expertly mimics breastfeeding, so that milk will only flow if your baby works to create a vacuum to remove the milk. (This in turn improves a baby’s sucking power and ability to transition back to the breast.) It also features no-drip technology to prevent spilling — even when the bottle’s turned upside down — and a vented nipple to cut down on gassiness. Pretty impressive!