Teach them how to sip from a straw with the Step 3 Mug from Combi. Once your child has mastered the Step 2 Mug, it's time for the Step 3, which allows a natural transition from drinking from a cup to drinking with a straw. Curved handles ensure that it's comfortable for little hands to hold, and the soft, flexible straw makes it easy to drink from. A locking cap is included to help prevent spills.