Why are you choose them? Health Materials: The collapsible travel cup made of food grades silicone, no smell, non-stick and keep your health. Space Saving: with the collapsible design, never take up your space. Inside Measuring Design: Easy to read with the measuring inside of the cup. PE Dust Lid: The tight and snugly fitting lids can prevent any dust and dist from the air. Portable Hook and Connective Hand Rope: Combination of both can string the cup and dust cover together to prevent accidental drop. Stainless Steel Cup Rim: The stainless steel rim at the top is strong and maintains the integrity of the collapsible cup, make the cup much easier to hold and drink. Easy to Clean: With the inner wall adopts smooth design, not easy to be sticky and just wash it under the running water(dishwasher available)