Bopp Hot Flask The Bopp Hot Flask is a stylish thermos flask with a good design in order to fill up to 600ml. The thermos flask is double walled. With stainless steel on both the inside and the outside. This will keep your beverages such as coffee, for hours at the right temperature. The thermos flask is BPA-free production. The cap can also be used as a mug and it has a cleverly designed earpiece so you can hold the cap easy.The thermos flask is easy to clean during washing, use hot water and some detergent and the thermos flask is ready to use again. You can print your own design or logo design on the bottle. You can print your design or logo in up to 4 colors. Also, you can engrave your logo. The thermos is available in different colors.