10 oz. for ages 12M+ with a BPA-free big kid spout
Interchangeable Lids: Lids can be interchanged between any Sippy Stackers cup
Summer Infant Sippy Stackers encourage your child's independence. The guaranteed spill-proof cups are perfect for little ones at home or on-the-go. The interchangeable lids can be removed, and cups can be stacked for easy storage. The Simple Sip Rim has threads on the inside to provide a smooth surface for drinking when cups are used without lids for older children.