The Dr. Brown's Training Cups feature a Sip Activated Valve that is only activated by baby's mouth when drinking. There is no mess when baby is not drinking from this spill proof cup. All parts in the Dr. Brown's Trainer Cup System are interchangeable. The unique soft spout helps babies transition from bottle to cup. Cups are BPA free and dishwasher safe (top rack only). Contents include: 6oz/180ml cup, sip activated valve, soft spout cap, removable handles, protective lid and instructions.