Feggs

They're called 'fegg' because they are foldable and kinda look like massive eggs. Ok, jokes aside: Foldable. Ethical. Go-Anywhere. Glass. Let me sum up why they're awesome:

unbreakable (can't smash in your bag)
reusable | sustainable
made from food grade silicone, so odourless | flavourless
set of two as shown
350ml | portable | lightweight
dishwasher safe