The Ti-Double H300 Stacking Mug is made of Japanese titanium utilizing a historic manufacturing process. With its double-wall insulation, the H300 Stacking Mug is designed for hot and cold beverages. Pair the H300 Ti-Double Stacking Mug with the Ti-Double H450 Stacking Mug or Ti-Double H200 Stacking Mug, and nest them together for easy storage at home or outdoors.