The Vacuum Of Thermos Flask'S Cup Blocks Heat Transfer. The Products Hold Liquid Heat Above 42 C For Up To 6 Hours And Liquid Cooling Below 10 C For Up To 5 Hours. This Is Longer Than Other Vacuum Bottles. (After 24 Hours At 100 C Water, The Temperature Is Maintained At About 40 C). The Inner Wall Of The Small Flask Is Made Of 304 Grade Food Grade Stainless Steel And The Outer Case Is Made Of High Quality 204 Stainless Steel.

It Has Been Approved By The Fda For Your Drinking Needs. Of Course, 100% Does Not Contain Bpa. Hot Flask'S Insulated Thermos Is Designed With A Condensation-Free Exterior That Keeps Your Hands Dry. Small Flask Wth Ultra Capacity Battery: The Lithium Battery If Of Large Capacity. The Screen Turn Off Automatically When Not In Use So It Can Reach A Battery Life Of 2 Years. No Need To Worry About Battery Recharge Daily.