Dr. Brown's® Milestones™ Sippy Bottle is the perfect first step for baby's transition from bottle to cup. Introducing a sippy spout has never been simpler. The soft silicone sippy spout is used in place of the nipple on the Dr. Brown's bottle that's already familiar to baby, while the snap-on cap keeps the spout clean when on-the-go. The sippy spout fits any Dr. Brown's® Options+™ Narrow bottle after the internal vent is removed. All parts are safe for use in dishwasher (top rack only), electric and microwave sterilizers or boiling water. 6m+.