Now, you may not have even known that collapsible cups exist, but this is your lucky day. This is a great thing to have in your everyday life, but also when it comes to traveling. They are super handy when the flight attendants come by with the small cups of water. You can have them fill your cup, but you don't have to worry about it taking up too much space in your bag or having a bottle full of liquids while going through security.
You always want to make sure that you have some extra space in your bag when traveling, and getting collapsible items is a great way to do that.