Double layer stainless steelThe double stainless steel of the case ensures good insulation and significantly reduces heat loss. The air gap vacuum layer can eliminate heat transfer and convectio. In any season, it can keep the heat for 6 hours and cool for 9 hours. Meet your drinking temperature needs at any time. | Food grade 304 stainless steelWhen developing this thermos flask, we have thought of everything, especially your safety - from BPA-free lid to the high-quality 304 stainless steel, so you can enjoy every sip with confidence! | straw capsTravel Mug with Lid, Modified Straw Lid for Using Straws and Lifting Th | Straws, Straw BrushesThe cups are easy to clean and are not recommended for the dishwasher. Supplied with straw and straw brush. |