The X-Mug has a flat rigid ring around the rim to keep it sturdy and easy to drink from. The rigid ring maintains the shape of the X-Mug yet still allows it to be collapsed to a disk that will fit in the palm of your hand.
Features
X-Mug has a rigid flat ring within the rim holds its shape Spill resistant, versatile shape Unbreakable, folds flat for compact packing Unique design Holds 480 mL