These collapsible travel cups are made of food grades silicone offered stainless steel rim and plastic lid. Easy to wash, odorless, non-staining, durable, flexible & reusable. Can be hung on the bag of a connective hand rope and portable hook. Easy to read with the measuring inside of the cup. Much easier to hold and drink from the stainless steel rim of the cup. Tight fitting the lid prevents any dust and dirt to get close. Fits well in your pocket, purse, backpack, suitcase and takes up no space, ideal for outdoor hiking, camping, travel, and sport events.