The double walled vacuum insulated construction prevents condensation collecting on the outside of the bottle while keeping drinks hot for 24 hours and cold for 12 hours. Made from high quality 18/8 stainless steel its super durable, 100% food grade, odourless and BPA-free. The hygienic electro-polished interior surface resists bacterial growth and makes cleaning easy, while the external powder-coated finish provides a little extra grip. Designed for ultimate portability, the durable stainless steel handle is built for easy carrying and attachment to backpacks. These bottles are perfectly sized for day long hydration, from yoga to work, all day at school, festivals and the outdoors.