Sip, Sip, Hooray!Dr. Brown’s Milestones Narrow Sippy Bottle is the perfect first step for baby’s transition from bottle to cup. 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.BPA free.As baby’s feeding progresses, transition to soft silicone sippy spout to teach new drinking skills.The soft silicone sippy spout is used in place of the nipple on the Dr. Brown’s bottle.that’s already familiar to baby.Snap-on cap keeps the spout clean when on the go.