Maestro Flask, Vacusteel Water BottleProduct Description Introducing the Maestro Flask by Cello, a cutting edge stainless steel water bottle that elevates your hydration experience. Engineered with patented vacuum technology, this Vacusteel flask ensures your beverages stay refreshingly cold or piping hot for hours on end. Its double walled insulation, coupled with an inner copper coating and thermoseal technology, guarantees superior temperature retention. With a spill free flip top lid