The X-Mug is constructed from a flexible, European standard compliant, food grade silicone.A rigid ring within the rim keeps it sturdy to hold onto and easy to drink out of, but still allows the mug to be collapsed to a disk that will fit in the palm of your hand!DetailsFolds flat for compact packingFood grade flexible silicone sidesNylon ring at the top maintains shape and prevents scalded finger tips2 cup capacity (16 oz / 480 ml)Nests into the flat X Bowl & X PlateColor: Lime GreenDishwasher and microwave safe