High-end refillable bottles generally occupy a fair amount of space but the Space Shaker bottle is incredibly compact thanks to its fully collapsible design. Built to hold 600ml of liquid, the Space Shaker bottle can also easily collapse to be a third of its size when empty. The bottle isn't just restricted to water as it can safely contain juices and even protein shakes. This ability is thanks to its use of 100% BPA free food-grade plastic that also works marvelously in the bottles collapsing abilities.
When fully collapsed, the bottle can be easily packed away and three Space Shakers generally take up the same amount of space as a single 600ml reusable bottle. The bottle is also entirely dishwasher safe and features a secure o-ring to prevent leakage.
Image Credit: Space Shaker