The top lid doesn’t screw,the lid is not secured through threading or a sealing ring to the cup,so it's not sealed. The cup is about 12.7 ounces,It's probably smaller than expected. Specifications: Material: Glass Color:Transparent Size:12.7ounces;14x8.5cm/5.51x3.35inch Package Includes:1 × Stripe Coffee Glass Cup Note: 1.The lid is placed directly on the top of the cup and is not threaded so it cannot be tightened and sealed. 2.If there is some unsmoothness in the punching at the small hole of the cup lid, we actively solve these problems for you. 3.The box has been upgraded with a sponge package to ensure that the cup is not broken as much as possible. But the road will inevitably have collision, if the cups or straws or lids are broken, we actively solve these problems for you. As a high value glass cup, its vertical stripe design, perfect for the home, such as placed in the home living room, kitchen, home bar, to decorate the home better look. Pour your favorite drink in this striped glass cup and serve it with your favorite food,then enjoy a relaxing leisure time. Notice: Manual measurement, please allow slight errors on size. The color may exist slight difference due to different screen displays.