Refillable bottles are greatly convenient, as long they are filled up and consequently ensure the body liquid supply. Yet when empty they change to useless and place-consuming objects in our bags. When the bottle top of dreizueins is counterrotated to its bottom bowl the silicone container is compressed. That way the whole volume can be reduced to a third of its size and the bottle is transformed to a flat box. The developed compact form is supported by the rectractable valve that is pressed down into the bottle after the closing process. The valve of an air mattress was exemplary for this.