The stylish ichimatsu collection mugs are equipped with high quality double wall stainless steel vacuum insulation construction that keeps beverages hot or cold for hours. • stainless steel vacuum insulation keeps beverages hot or cold for hours • the twist-off lid makes the drinking experience more like drinking from a regular cup • compact lid design has fewer parts for easy cleaning • 2-step method for disassembly and reassembly of lid ensures no accidental leaks, and helps prevent the loss of parts • a special manufacturing technique was used to round the bottle opening, making it smooth and comfortable to the touch when drinking and cleaning • capacity: 16oz (0.48l) • 1-5/8" (4cm) wide mouth opening accommodates full-size ice cubes, and is easy to fill • made of bpa-free plastic and 18/8 stainless steel • the lids are interchangeable with sm-tae48, allowing for a wide choice of color combinations and use • "ichimatsu" is a two-toned checkerboard pattern that holds historical significance and recognition in japanese culture. In the mid-edo period, a popular kabuki actor named sanogawa ichimatsu was known for wearing pants with this pattern. • heat retention* : 189°f for 1 hr. / 160°f for 6 hrs. • cold retention** : 46°f for 6 hrs. • color : ichimatsu white (-wz), ichimatsu black (-bz), ichimatsu red (-rz), ichimatsu blue (-az) *rating is based on water at a starting temperature of 203°f (95°c) at a room temperature of 68°f (20°c) **rating is based on water at a starting temperature of 40°f (4°c) at a room temperature of 68°f (20°c)