Reusable Coffee Cup For that durable boost when on the move. A coffee-to-go is irreplaceable in many situations. For example, when you have to get up very early to use public transport. Or when you take a break from work and go for a walk outside to clear your mind. But also during a long city stroll. Coffee is the best no matter what. But out of this reusable coffee cup, it will taste even better. What is this coffee cup made of? The coffee cup is a mix of glass, cork and silicone. The glass cup is thick and heat-resistant and therefore ideal for hot coffee or tea. But this does not mean that the mug does not become blazing hot. You could quickly burn your fingers. The cork band is there to make sure this does not happen. It is also equipped with a silicone lid to prevent the cup from overflowing, which is waterproof and heat-resistant.