Double Vacuum Flask The Double Vacuum Flask is a bottle with two separate parts to make a drink. In total, the contents of the Double Vacuum Flask 850ml, the separate parts are 600ml and 250ml. The bottle has a black grip around it so that the bottle does not slip out of your hands when you pour your drink. The Double Vacuum Flask has two caps that you can use as cups for your drinks. The bottle is double walled so your drink stays at exactly the right temperature. You can print your own logo or design on the bottle so that it is more personal and can be used as a promotional tool. You can print your design or logo in up to 4 colors. Also, you can engrave your logo. The Double Vacuum Flask in one color available. The Double Vacuum Flask is BPA-free production.