High quality vacuum glass liner with excellent temperature retention; Heat 151°F @ 10 hrs / 124°F @ 24 hrs, Cold 46°F @ 10 hrs Vacuum liner made of Japan premium, medical-grade*-equivalent borosilicate glass (*Tested by a third-party laboratory and rated EP/USP Type I, which is the same as medical grade glass); Stain and odor resistant glass interior One-touch pour for quick and easy serve New "Ichimatsu” pattern, a bi-colored checkerboard pattern that has been in existence in Japan since ancient times To clean, rinse interior with warm water and wipe exterior