These outdoor collapsible cups are made of Food grade silicone(BPA Free). Capacity: 250 ml. Easy to carry and clean, there is a wrist strap on them allows you to attach them to your backpack, diaper bag,toiletry bags, or whatever you need to attach it to. The tab on the bottom of the cup makes it easy to open it up as well as making it more stable when placed on a flat surface. The mouth of the cup is reinforced with a metal ring so it doesn't collapse or flop around. it's made of food grade silicone , doesn't absorb flavors or smells,environmentally friendly and reusable.They all come with lids that go on tightly, keeping contaminates out of your cup. Wildly use for home/ outdoor, traveling and Hiking, to kids, to adults, for your pets. Size: 4'' x3 1/4"